Ashby-de-la-Zouch Castle became a tourist attraction as long ago as 1820, with the publication of Walter Scott's medieval romance Ivanhoe, a large part of which is set at the castle. It was originally built as a fortified Norman manor house in the 12th century, and remained intact until the English Civil War, when its use as a Royalist stronghold meant that the Parliamentarians subjected it to some fairly drastic post-war remodelling. But you can still climb the tower, and explore the underground passage from the tower to the kitchen basement.