The sober exterior of this vast house of worship (one of the largest in Castilla) belies the extraordinary riches within – it's widely known as 'La Bella Desconocida' (Unknown Beauty). The Puerta del Obispo (Bishop's Door) is the highlight of the facade. Once inside, head for the Capilla El Sagrario: its ceiling-high altarpiece tells the story of Christ in dozens of exquisite panels. The stone screen behind the choir stalls is a masterpiece of bas-relief, attributed to Gil de Siloé.
From the retrochoir, a plateresque stairwell leads to the crypt, a cleverly adapted remnant of the original Visigoth church; its simplicity is a pleasing contrast to the extravagance of the main sanctuary. Near the stairwell is the oak pulpit, with delicate carvings of the Evangelists by Juan de Ortiz.
Highlights of the attached Museo Catedralicio include an El Greco painting and exquisite Flemish tapestries. Don't miss the whimsical trick painting by 16th-century German artist Lucas Cranach the Elder. Looking straight on, it seems to be a surreal dreamscape that predates Dalí by some 400 years; only when viewed from the side is the true image revealed – a portrait of Emperor Carlos V.