Castles

Andalusia and Valencia hold most of them, with Castile and Leon and the Balearic Islands close behind. Most stand on a hilltop, a limestone crag or a cliff above a river, and many are ruins rather than restored palaces. Menorca is the outlier: harbour forts and watchtowers at sea level. Expect an uphill walk at almost every site, and book ahead where entry is by guided tour.