The Cathedral of Santa María sits just inside the walls, close to the bus stop, and is the natural starting point for any visit. The building spans several centuries of construction — Romanesque, Gothic, and Plateresque elements sit side by side in a way that would look awkward elsewhere but here feels organic.
The cloisters are the highlight. Walk slowly around and look at the column bases — they are carved with an unusual variety of figures, animals, and foliage, each one different, showing the playful hand of the Romanesque sculptors who worked here in the 12th century. The interior is quieter and cooler than the sun-blasted streets outside, with good choir stalls and an altarpiece worth pausing in front of.
Admission to the cloister and tower is a few euros; the main nave is free. The tower gives good views over the town and the surrounding countryside toward Portugal.