This sturdy 18th-century fortress commands the surrounding plains from a low hill 1km northwest of the centre. The complex is a wonder of military engineering: it sprawls over 32 hectares, with the capacity for 6000 men to march within its walls and snooze in military barracks that are on display today. The admission fee includes a clanking audio guide (nearly as old as the castle) to help navigate the site. Book ahead for group guided tours (€10 to €15 per person). Opening hours vary seasonally.
Built in 1750 to repel French invaders, it nevertheless fell to its Gallic neighbours – both in 1794 and 1808. Spain’s Republican government held its final meeting of the civil war (on 8 February, 1939) in the dungeons.
