This medieval fortress has had an eventful history. Built around 1380-90 and changing hands on numerous occasions, the castle was destroyed in the 15C. 15m-high ramparts and 2m-thick walls once surrounded buildings which have now disappeared. Only two square towers standing on volcanic basalt crags remain - the Old Woman's Tower (47m) and the Maiden's Tower (57m). Discovered by Romantic poets and painters in the 19C, these ruins have exerted a fascination over visitors ever since.