From English Heritage website -
“Sutton Bank is well known as the home of Kilburn White Horse, created in 1857, and of the Yorkshire Glider Club, founded in 1933. But very few people are aware that the promontory is also the site of one of the most important prehistoric monuments in the region: a giant hillfort built in the Iron Age, around 400 BC. The guided tour will be on Saturday 22nd May 2004. Please note that places on this tour are reserved for English Heritage Members only.
For further information about the tour, contact Jonathan Hogan in English Heritage’s York office on 01904 601 971 901 or e-mail [email protected] ”