Park at ANSTO. Head straight down the trail, just after the first 2 small bridges go left up the hill instead of down. After about a 4-6min climb, turn right onto a fire trail. After about 10sec on the fire trail veer right onto single track, follow this trail and you will find lots of jumps and bridges/ladders going down. Warning; some of them are loose so be sure to check them out before using them.