Pete A.
Google
Do not miss York's Walls. You can walk most of the way around the city, and in the Autumn the leaves of nearby trees look stunning. You need a head for heights, because most of the walls are not protected by railings on the inside edge, with a 3 meter drop to grass or thorns, but nobody seemed worried. The best views are from the highest point of the walls near the railway station, looking towards York Minster. The unexpected bonus is Baile Hill, a FREE mound beside the wall, which I preferred to its more famous cousin, £9-to-enter and no-views Clifford's Tower.