The Concrete Pillars On Top Of British Hills: Trig Points

tomscott.com - / tomscott - Around the United Kingdom there are odd concrete pillars on the top of hills, built to last for decades if not centuries. They've got a cryptic marking on them, and the words "Ordnance Survey Triangulation Station".
What are they? (They're trig points.) Who put them there? (Brigadier Martin Hotine and thousands of people working with him.) And why? (To get an accurate map of the UK, with maths.)

[@PickledWhispers]

You say that they're little more than a landmark for hill-walkers. I take issue with that good sir! In fact, they're still incredibly useful for archaeologists. I went on a fair few digs as a student, and we always broke out the theodolites and ranging rods to make accurate maps of each dig site. Granted that's going back a few years, but even with GPS and more modern, digital, self-levelling, laser-based theodolites (which most archaeological societies don't have access to due to limited funding), the stones are still useful as a base point because they're all at a known height above sea level.

[@TomScottGo]

Wabznasm Fantastic! It's great to know they've still got some use.

[@volvo-enjoyer]

interesting :D

[@sarahprunierlaw9147]

+

[@Patriot1066Tom]

Mostly, they are useful for surveyors. Archeology doesn't necessary need an accurate triangulation.

[@Sam-gf6ue]

@@Patriot1066Tom yes it does. especially on larger sites, or working out relationships between local sites.

[@xrayblaster4874]

I feel like I've seen all your videos, but then I find something new from 4 years ago

[@elanorwoodhams7811]

An interesting thing about surveying in New Zealand I heard from a (geology) lecturer, is that our trig points were surveyed a few times, getting different results each time. This was probably really frustrating having survey data that didn't seem to add up, but it turns out New Zealand is slowly changing shape due to the faults through it, including when there isn't an earthquake

[@JoelGalilee]

Although I live in York, I go walking in the mountains of Scotland in the holidays, and it's insane how remote some of the hills are that have trigpoints at the top, it's extremely difficult walking there at all, let alone lugging tons of concrete to build it. A fascinating system, I can only hope this legacy never dies.

[@shawnpitman876]

what is with you all and "lugging" the concrete to these locations by hand? Don't you think your forefathers would be smart enough at the very least to USE HORSES?!

[@d6853]

@@shawnpitman876 They built these a long time ago, horses weren’t invented yet.

[@truthfulfreedomfighter9123]

@@shawnpitman876 up a very steep hill

[@shawnpitman876]

@@truthfulfreedomfighter9123 horses with a pulley system.

[@jesseg7183]

AND THAT IS SOMETHING YOU MIGHT NOT HAVE KNOWN! The video feels empty without that at the end

[@pieter1102]

I always fill that in at the end, even before Tom can say it. This time I was a lone voice. Bring back the SPOKEN punch line! *****

[@safe-keeper1042]

Because everyone knoew about trip points who can you not you barbarian!11

[@thetessellater9163]

@@safe-keeper1042 - Que? Please translate into understandable language.

[@MarkAtkin]

But this is something which I thought everybody knew. At least anybody who has ever climbed a hill and seen one at the top. OK, I didn't know the name of the brigadier, but the reason they are there was, I thought, common knowledge.

[@Davemcfc]

I went to see Wales' highest trig pillar in November. We made it and it was truly awful. So we are going again in June!

[@clockworkkirlia7475]

Ahh, I remember this feeling fondly from Scouts. "Why do you enjoy camping?" "Well it's wet and cramped and exhausting and I tend to either burn myself or get ill." "So... you don't?" "It's the greatest fun ever. Really. You should try it."

[@kennethflorek8532]

I'm from the US, not the UK. I worked (as the labor ) in the '70's with some government surveyors while an expressway was laid out for construction. The surveyors have lists of markers that have exactly known positions, are believed to never change, and are illegal to alter without authority. The surveyors considered these reference locations, including height, known within tiny fractions of an inch. The most usual markers were in locked handholes in a street, inside of which is a metal stud with markings. Some were pins driven into the masonry of large buildings below windows that were beyond reach and sight without a ladder. I suppose that was their protection. There were lots of these markers to work from, and I suppose to cross-check. In fact an eighth of an inch off in the length of a mile was worrisome to one surveyor. In some cases a building with a marker was gone in spite of the markers protected status. There is no enforcement. The surveyors update and report the status. I was amazed that there were these sort-of-secret markers all around that you would go by without ever knowing they were there.

[@HB-ps6rn]

I was rock climbing the other day on some private property and found a marker adhered to the top of a rock tower surrounded by some old wooden triangles. It was from the US Coast and Geodetic Survey with the date 1963 and stated there was $250 dollar fine for removing it. My friend and I were pretty surprised to see it in the middle of nowhere, however it must have been a cool job for those who installed it.

[@clockworkkirlia7475]

The world is full of languages that only a few people can speak (comparatively). Surveyors, engineers, programmers, anthropologists... It amazes me every time one gets pointed out.

[@skwyd42]

I’m a licensed land surveyor in the State of California. Those “secret markers” aren’t so secret and that hey are everywhere! There’s a good chance that there are several survey monuments within 2 miles of you. If you live in town, there’s probably several within 1000 feet of you. They aren’t as steadfast and precise as many would like to think (including some surveyors) but they are a physical monument with legal significance. The fine for damaging or destroying them is not enforced nor is it sufficient penalty for willful damage, in my opinion. But, nonetheless, I use them daily to establish legal property boundaries and the limits of various property rights.

[@Liggliluff]

_> "I'm from the US, not the UK."_ Why did you say it like that? ... Personally, I'm from Sweden, not Finland.

[@kennethflorek8532]

@@Liggliluff I don't understand the question. This video is by a person in the UK, about the UK. My comment is about the US, not the UK, since I only know about the US, not the UK. If I didn't tell people that, they would think I was talking about the UK, not the US. That would be confusing, if not baffling, because the US generally does things differently than the UK. People in the UK often say the US does things just to be different. Actually, we don't keep track of how things are done in the UK, so we don't know how the UK does things in order that we could do them differently, assuming we wanted to. We don't speak differently in the US motivated by the desire to speak differently than the UK. We are quite happy to do as we please, and we are quite happy to have the UK, and everywhere else, do whatever they please. The only real reason for the American Revolution was to keep things the same, while the British Empire decided they were going to change things. American colonists loved the British Empire; their ways, and their notions. The whole unpleasantness could have been avoided.

[@birdmn9930]

"When will trigonometry be useful in real life?"

[@TS_Mind_Swept]

Never, because GPS killed and trigonometry star

[@paulgrimmond6296]

Because things are still surveyed and it is still more accurate than GPS, especially on small scale and in cities, or underground or in areas unable to get a clear view shot. Trust me, the game is far from dead.

[@Asiliea]

@@Saucy-ws6jc While I agree about general problem solving, I'm gonna be pedantic and say that physical _brain_ health doesn't improve by it knowing trigonometry. That being said, it definitely can help the average person's _mind_ with increased spatial and architectural awareness. Both of which come in handy if you move your body at all, especially through/over/around/under physical structures.

[@ralph9182]

@@Asiliea learn trig or bang your head

[@varrjames186]

I thought exactly the same thing when learning Pi at school...40 years later, I actually used it to work out if one monster pizza @$20 was better value than 2 large pizzas @$10 each. It turned out that you got 5% more pizza with the 2 large ones...so it all boils down to if you're a fan of the crust or not.

[@GamesFromSpace]

GPS works pretty much the same way, except they placed the markers much higher (and they're less stationary).

[@amperzand9162]

They also need replacing more frequently.

[@gsvick]

Except GPS is not based on measuring angles. It's based on very precise measurements of time, which can be used to figure out your position, relative to the the satellites.

[@jacklewis1]

@@gsvick and the maths is a lot more complicated, Both special and general relativity are required to obtain an accurate distance from the satellite, then trigonometry using the distance from multiple satellites to work out your position.

[@aformofmatter8913]

It'd be cool to see some post-apocalypse story involving an attempt to re-map the land (both because many maps were lost, but also to account for changes brought on by the apocalypse) where these played a role

[@franzfanz]

In New Zealand they sent out hundreds of guys to survey the country. Very important work when you want to parcel it up for colonial settlers. As New Zealand is a lot more mountainous and was covered in forest it must have been a hellish job.

[@cr10001]

The British did that everywhere (and probably other European colonial powers too). I think I remember reading that, at the start of the 20th century, the highest point on earth that had been reached at that time was by some unknown Indian survey assistant with a survey staff.

[@nigeldepledge3790]

It's often a great comfort, after slogging your way up any kind of hill, to arrive at the trig point. Partly because, at a trig point, the OS map tells you exactly where you are; and partly because of the sense of achievement it gives to reach it.

[@sfsoma]

As usual, very well done. Interesting feature to write into a post-apocalyptic novel.

[@dash8brj]

Don't be near one (or any other high point) in a thunderstorm. My mates and I had hiked up the hill to the trig station in a local national park here in Australia. The view was awesome, thunderstoms rolling in from 3 directions. Suddenly there was a blinding flash and deafening roar. All 3 of us were luckly to be alive as the pillar got hit by 20 million volts at 500, 000 amps. The thunderstoms were miles away but just goes to show that lightning can strike anywhere without warning.

[@RichardB1983]

You could do a follow-up video about bench marks on British buildings. The horizontal cut mark with 3 near vertical cut marks below.

[@clockworkkirlia7475]

...BENCH MARKS ARE A THING? *of course they're a real thing*

[@djpalmer31]

Great video Tom. The hooks are actually for tying down the tripod legs or the beacons that were placed over the top during observations. For an earlier history of the OS check out Rachel Hewitt's book Map of a Nation.

[@claytonfs]

Someday, Tom Scott 2.0 will be piloting a jet pack alongside a global positioning satellite in space and beaming historical information about it into our consciousnesses.

[@custard131]

this is pretty interesting. i always thought they were just there for walkers to balance a flask/mug and box of biscuits on :)

[@FlightlessAviator]

That is such a British thing to take on a hike. Ever heard of sandwiches?

[@SirCutRy]

There are these also at least in Finland. It was used to construct the map of Europe. We went to the site of one of these. Thanks for explaining the concept well.

[@DarkSyster]

Here in Canada, they are known as "Geodetic Survey Benchmarks". GPS is accurate to a few metres unless you're using the military grade version. The benchmarks are said to be accurate to 2cm horizontally and 4cm vertically. So in terms of precision, a theodolite and a benchmark will give you more precise results than GPS. Sometimes, that's important.

[@safepethaven]

Thank you for this. As a teacher of math & sciences since 1968, I'm always so frustrated with each new year's "crop" of students who are a.] unprepared in even basic arithmetic skills by the time they reach high school; b.] say they "hate" math, and c.] see absolutely NO purpose for math OR the need to learn ANY math. Poor misguided souls. No, not everyone will go on to us their PhD degree to develop new things that will serve and improve the world, but I wish these negative nancys would at least acknowledge the power & contribution that various pure & applied math specialties have had that have resulted in making their own lives so much better -- or at least more convenient.

[@Alternatevil]

Gosh! These videos are so fascinating. There are so many interesting things to learn about the purpose of the relatively mundane artifacts of the landscape.

[@piros44]

Interesting! This is the British version of our benchmark medallions cemented to rocks around the US. I’ve come across quite a few of them over the years.

[@fadetounforgiven]

We also have those in Spain, they're called "vértices geodésicos" and work just the same. They're on high points and their design is a bit different, just a squared box with a kind of concret "pipe" vertically on top of it. And, as it's written in every and each of them, if you destroy it in anyway, you will be prosecuted.

[@maxsnts]

Portugal also use them. And i think they are still in use for land surveying has a way to "integrate" the surveyed land plot accurately with the rest of the map. Maybe GPS took over lately.

[@FrozenBusChannel]

Lots of these still exist in Hong Kong (former British colony), and are used in surveying

[@neil340]

Can't tell if you're really smart, or if it's just your English accent. All kidding aside, it was informative!

[@hillsinhighplaces]

This is the video that got me into Tom's vids after I watched it in a high school maths class :)

[@ajs41]

I'm watching all of Tom's videos, starting with the oldest one from 2006. It's taken about 3 days to get to this one. Probably take about a week to watch them all.

[@chrispeoples4606]

A fundamental importance of the trig points is that they provide the ground truth to which the accuracy of GPS fixes can be compared.

[@LewisGreyChemGeek]

In New Zealand we have these as well, although they are not pillars, they are steel or something like that.

[@dommorris8163]

same in Australia. they have circular metal plates on top of a pole on top of concrete.

[@derekscanlan4641]

the ones in Ireland (at least Dublin and Wicklow) are same as in this video

[@quentintubb]

the ones ive seen in new zealand are round concrete poles with a hole in them

[@shawnpitman876]

@@derekscanlan4641 duh? same country bud.

[@davidholden2658]

@@shawnpitman876 errr, Dublin and Wicklow are in a very different country and were when these were built.

[@RyanMcMurraySound]

Great quick video. Nice work.

[@Warp_Portal]

"I'm on top of a hill" 430,000 people: "Interesting..."

[@RealRivalDieHard]

Your vid explain everything i need to know about trig point here in malaysia..alot of thanks (thanks alot)

[@ChaplinONLINE]

Somethings I did know: that trig are a thing, used them on my Duke of Edinburgh expeditions and was able to see other trig points from them and use them to know exactly where I was in the wilderness... Something I did not know: that they relate to trigonometry, because if I did then damn I would've payed more attention and tried to learn trigonometry in school, and that there are 6000 of them... I assumed that there were around 1000 max and only a countryside thing. Well. This was a useful video! Thanks!

[@DarenPage]

My dad told me about this many many moons ago and from that I know of two trig points around the Ridgeway; one just up from Foxhill and the other on top of the Uffington White Horse. Even more incidental is the fact my dad even bagged himself a working theodolite, should still be around, I'd love to try it out and see how accurate it is...

[@burdizdawurd1516Official]

Ah, that's a bound. It's a survey monument- in my country it is illegal to destroy or move them. And for good reason, because you would not believe how hard land surveying is. I've use the GPS system once, it was tedious. I much rather prefer crawling through the forest looking for monuments called for on a map from 1940, none of which still exist due to recent construction. But the one drill hole in the stone wall that to the untrained eye is only a mere divot: glorious drill hole! It is nice when the iron rods have caps on them, but if every bound stuck out of the ground like that my job would be simple. "Where am I? Am I in Norfolk?" "No this is the UK." "That's it, I'm moving."

[@erictaylor5462]

And now you know why they call it "Angle Land" or England.

[@josepherrami3434]

>not sure if joke

[@josepherrami3434]

:(

[@erictaylor5462]

joseph errami Having seen a lot of comments I think I can know why there might be some small chance that I'm not joking.

[@erictaylor5462]

Alwin Priven I know that. I've known it for a while too.

[@radioactivated]

lmao

[@petrazoliukas]

And what about curvature of the earth? Do those calculation methods used back then included it in calculating actual ground distances?

[@PickledWhispers]

They did indeed. Also; atmospheric distortion.

[@gentlegiantJGC]

Nice work. I had seen them and knew they were used to make the os maps but never knew how

[@anthological2117]

1:02 I know it's just the angle of the light, but your left eye looks unbelievably different from your right here

[@jmckendry84]

Ah, I always thought that they were intended to be used to measure height (though I suppose they do that too?) but seeing the triangles making up the map makes a lot more sense.

[@FlightlessAviator]

We have a few of these in New Zealand, but they're less squat concrete stumps, and more often spindly wooden pyramid towers a couple of metres high, and yes, they usually just mark the end of an arduous hike (or 'tramp' as it's known here) and a good view. (especially if you climb the trig... I'm sure that's allowed, right?... )

[@southamptononvideo2439]

Tom, Brilliant exposition. Thank you very much! Kingsley Miller

[@thetessellater9163]

As a resident of the rural area that became the 'new city' of Milton Keynes, in North Buckinghamshire, I remember one of these on the hill which was subsequently 'shaved flat', or decapitated, to accommodate the ' centre:mk' - Milton Keynes central shopping building and the surrounding car parking.

[@Feraloidies]

Lots of them in Australia, too. different designs, though.

[@WillKemp]

Yes, and spatial datasets of their locations are free to download - in at least some jurisdictions

[@BadJellyman100]

I've located plenty of these here in the states. Around five in New Mexico, three in Arizona, somewhere upwards of twenty in Colorado (home state), and one in Utah. Haven't done much hiking or stuff outside of this general area, but I do plan on doing more all over the states. All of the ones I've seen are driven into the ground though. I'm sure there are some that are on concrete pillars, in areas where vegetation would otherwise cover it up.

[@JS9678]

Really like your vids, keep up the good work.

[@emperorspock3506]

There's an early-1800's World Heritage Site in Northern and Eastern Europe, that's similar to this (although it was for measuring the curvature of the Earth, not maps): en.wikipedia.org/wiki/Struve_Geodetic_Arc

[@tmcclennen1]

It might be interesting to make a video about the ordnance maps that those trig points were used in the making of, and the role that those maps played in defensive planning during the Second World War. I'm put in mind of Churchill's "We shall go on the end." speech. Had the fighting spread past the "beaches and landing grounds" and into "the fields and in the streets" and the hills of England, I imagine that it would be a huge advantage for the defenders to have highly accurate maps, so long as those maps could be kept out of the hands of the enemy.

[@JQ3B94]

They are still good navigation aids , as you can use them to find where you are with a compass and a pair of binoculars and a map

[@retepsemaj96]

A good episode! One that I actually new about!

[@cyrex686]

If you look around, you will still see sidewalk benchmarks everywhere. Your block probably had one on it. Surveyers use them when determining properity lines and such.

[@p3falien233]

as always very interesting Tom. thanks !

[@jodhan90]

In Germany they still use these old Points. They look different, but their position is still in a official register. And they use them for important surveys.

[@coops1964golf]

we had one of these on the farm i grew up on....it's in deepest lincolnshire,barely above sea level

[@milksheihk]

The trig stations in my area of Australia are that shape & size but are made of tightly packed rocks from the surrounding area, you'd think vandals would just kick them down but strangely nobody ever does, they aren't that hard to get to, it's not unusual for people to camp there or have picnics, there's certainly grafitti up there.

[@cjmillsnun]

Many of the old trig points have gone now. A few like that one remain that are used for GPS occasionally

[@dannymurphy1779]

Guys if you lugged concrete up there it would start setting! You would also need a lot of shuttering to make that obilisk. Surely they cast them in a batch and simply took them up on a tractor!

[@prasanttwo281]

0:56 so thats what the shadow of a face looks like from the side. I've been trying to turn my eyes as much to the side as possible to see it for years. (It never came to mind while looking at other peoples shadows)

[@philipmoorcroft7406]

Tom Scott, thank you for a simple and very well delivered explanation.

[@tomm.ymacleod9347]

We have theses too but they’re white concrete cylinders with a black pole and wind vane on top.

[@MichaelSHartman]

I can't say which is more accurate within the local area. My GPS phone app has shown a large relatively large range for all three coordinates. As you have said in a previous video tectonic plate activity may have come into play.

[@nathanhouston5]

I was off the beaten track in a forest or Northern Ireland and stumbled across one of these and hasn’t a notion as to what it was!

[@VitorMadeira]

And if you visit Portugal, try to find the "talefos" or PONTOS GEODÉSICOS on top of the hills. Greetings.

[@corndogrequiem1728]

I don't remember learning trig at all... Guess that explains why only 1/4 of the public schools I attended exist now.

[@obsidiandeluxe4474]

Leave that trig point alone. It’s just vibing.

[@amanofmanyparts9120]

Interesting (kinda) factoid: Ordnance relates to military weaponry. Meaning if you know where you are and you know where the enemy is, you can target your 'big guns' more accurately. Unfortunately this means the enemy is your neighbour or brother.

[@josephbeineke1175]

I found these around a week ago while hiking in the mountains in Hong Kong. I was wondering what they were but now I know. So it is a Hong Kong thing as well!

[@adrianbaker5916]

Well it used to belong to us

[@rashkavar]

You do still need to do one accurate measurement. Presumably somewhere in this network there are two of these surveying monuments (as the Canadian version is known) that are a precise distance apart, something short enough to be easily measured precisely.

[@Wyattporter]

0:07 I believe the technical term is "pillock".

[@yungstallion2201]

I live a mile away from one of these in the middle of nowhere in Wales

[@mollielovett1476]

I knew this one! We have them in Ireland. I guessed it was for trigonometry and I knew it was for maps but its cool to learn about theodolites. :-)

[@dommorris8163]

in Australia they have thesd but they have large metal things on top

[@rjfaber1991]

We've got the things here in the Netherlands as well. I didn't know they were put there so recently though, I always figured they were a 19th century thing...

[@JH1010IsAwesome]

I wouldn't be surprised if they were put there in the 19th century in your country, people have been using concrete and trigonometry to create maps since 1776, I'm amazed the UK didn't catch on sooner

[@maxsnts]

Its very possible. In Portugal the first ones were built in the 18th century... but the french invaded... and we did not resume work on them until we kick them off hehe

[@LotsOfS]

Netherlands has hills? The closest thing to a hill ive seen there was a bridge

[@rjfaber1991]

LotsOfS Then you've only been in the Western provinces of the Netherlands. There are plenty of hills in Limburg, Brabant, Guelders and Overijssel. Even the province of Utrecht has a few. Of course, these hills are not very high by global standards, the highest peak in the Netherlands doesn't even reach 400m, but compared to the utter flatness of the rest of the country, they definitely do stand out.

[@rogerwilco2]

The Dutch call anything over a few meters in height a hill as it stands out in an otherwise completely flat landscape. See for example the Hondsrug, Utrechtse' heuvelrug, Montferland, Things over 50 meters tall tend to be called mountains. ("berg" in Dutch), See for example Sint-Pietersberg, Vaalserberg, Lemelerberg, Cauberg, Amerongse Berg, Havelterberg. Although things as low as 5-10 metres might end up with -berg, e.g. Hasseberg, Berg van Troje.

[@rifdysamsudin6735]

great video, thanks!

[@ronburgundy8031]

I found this video. . . trig-ering.

[@williamsatterthwaite6063]

But why are the concrete, is that not a bit heavy to lug up a hill? We also have them here in New Zealand, but they are a wooden pyramid structure.

[@williamsatterthwaite6063]

+Cáca Milis sa Seomra Spraoi Oh there some solid weather-resistant-painted wood. I also just realised some have a concrete base anyway. i.imgur.com/LTU6Bp1.jpg

[@williamsatterthwaite6063]

+William Satterthwaite Excuse the terrible camera, that's Rangitoto Island from about a year ago. www.google.co.nz/maps/place/Rangitoto+Island+Scenic+Reserve/@-36.7895206,174.8693622,8877m/data=!3m1!1e3!4m2!3m1!1s0x0000000000000000:0x0f00ef62249ca3f0!6m1!1e1?hl=en&hl=en

[@cr10001]

The wooden pyramids are for 'sighting' from other locations, I think. If you look under the pyramid, I think you will find, directly below the centre of it, a small bronze plaque which is the actual survey mark.

[@nickbarber2080]

These appear to sere some ritual function,placed as they are on hill-tops away from settlement.

[@BluishGreenPro]

Very interesting! You might want to run this video through KZbin's stabilizer though, a bit shaky.

[@Scapestoat]

How peculiar! This is something I indeed did not know. My country is too flat to do something like that, so it's a smart yet alien concept to me. :)

[@jkennedy299]

We have those in Australia too!

[@radiocative6296]

I wonder what people in the future will think about all these weird little concrete obelisks on top of hills and mountains....

[@atahservices2840]

There also very good for /p Amateur Radio Activation

[@ThePixel1983]

*Soundtrack of TheEnglishmanWhoWentUpAHillAndCameDownAMountain starts playing*

[@a1yallop]

Brilliant. When the satellites are down or destroyed, the concrete blocks will still be standing and those of us who did at the very least GCE O'level maths will be able to calculate distances.

[@MrRobinhalligan]

Now that is something i did know cas we have trig points all over New Zealand

[@BralessandBananas]

Awesome!

[@chan.sorman]

Critch (pro. Cr eye sch) stand has one.

[@noahburns6042]

Me and my dad go trigpointing (trigonometrical point hunting)

[@saquoiafighter]

2,495 yards? Cool, and in 1936 the length of a yard was a uniform idea... Oh, wait.

[@ryanknight3366]

I have spotted on of these on my walk today but weirdly its not on a hill. Would you know why that is.

[@Herdatec]

*cough* *Gauss* *cough* Oh, I never thought there could be some patriotic feelings left in us germans. I know he wasnt the first but just like Watt with the steam engine, Gauss greatly improved the method by reinventing Gaussian elimination and the Heliotrop.

[@Stinger503]

If anyone's interested Waymarking.com has a large database of benchmarks/trig points that you can visit all over the world. There's even a category for ones in Disney theme parks. www.waymarking.com/cat/details.aspx?f=1&guid=905a74da-86b5-430d-94fb-d8be675283f7

[@TheLoxxxton]

I'm working back through the videos bare with me

[@soysasamitha]

is that brandon hill? i miss bristol :(

[@OKRolling]

Yeah, I live in the fens... I have to go a long way to my nearest hill. Are there trig points in cambrigeshire?

[@RichardB1983]

There are quite a few trig points in Cambridgeshire. If you have an Ordnance Survey map of the area (or look on Bing Maps in the UK and select "Ordnance Survey Map") - they're marked on the map as a small blue triangle with a dot in it. E.g. have a look just north west of the village of Witchford (which is just west of Ely). There's one there just near the A142.

[@astrojg0]

Theodolites (Nowerdays combined with lasers to measure distances as a total station) can actually be more accurate than gps.

[@OnkelJajusBahn]

Here in Austria we have crosses on each mountain.

[@howardchambers9679]

And the clue to "Ordinance Survey" is in the name.

[@101325]

It's actually Ordnance. Meaning Artillery. " The agency's name indicates its original military purpose, which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Wikipedia"

[@finlay9911]

I live right next to one in markfield leicestershire