Warwick castle is commercial, but it' is a great castle! You can walk around the top of the walls(!), and the countryside is beautiful.. Oxford has some of the oldest pubs in England, and a really good natural history museum and antiquity museums. Parks and greenery on the eastern side, the river on the western side, and wonderful old buildings in the centre.And you're on the left hand edge of the Cotswolds. It's good for shopping too.