The Radcliffe Camera is a circular building in Oxford, designed by James Gibbs in the 18th century to house the Radcliffe Science Library. It's a standout feature of the university and the city! It's still used as a working reading room for the Bodleian Library and is a key landmark in Oxford.
You can only see inside as part of the full 90 minute tour of the Bodleian Library. This tour currently only runs on Wednesdays, Saturdays and Sundays and is for kids 11 and older. If you can't make the full tour, at least stop by the outside for a picture! You can check for tour tickets here.