Ávila's splendid 12th-century walls stretch for 2.5km atop the remains of earlier Roman and Muslim battlements, with 88 watchtowers and more than 2500 turrets. Two sections can be climbed — a 300m stretch from the Puerta del Alcázar and a longer 1300m stretch from the Puerta de los Leales. At night, when illuminated to magical effect, you'll wonder if you've stumbled into a fairy tale.