In Praça Dom Sancho II, named in honor of the king who reconstructed the town, stands the Sé (cathedral). Under a cone-shape dome, it's a forbidding fortresslike building decorated with gargoyles, turrets, and a florid Manueline portal. The cathedral opens onto a black-and-white diamond square. It's open daily from 10am to noon and 2 to 6pm. A short walk up the hill to the right of the cathedral leads to Largo de Santa Clara, a small plaza that holds an odd Manueline pillory with four wrought-iron dragon heads.
On the south side of Largo de Santa Clara is the Igreja de Nossa Senhora de Consolação (Church of Our Lady of Consolation), a 16th-century octagonal Renaissance building with a cupola lined in 17th-century azulejos (tiles). It's open daily 9am to 12:30pm and 2 to 5pm.
The castelo (castle), Praça da República, built by the Moors and strengthened by Christian rulers in the 14th and 16th centuries, offers a panoramic view of the town, its fortifications, and the surrounding countryside. It's open daily from 9:30am to 1pm and 2:30 to 5pm. (It closes at 5:30pm Oct 10 to Apr 1.)