Porto Cathedral

This guide to Porto Cathedral centers on a 1387 wedding: English princess Philippa of Lancaster married King John the First inside these granite walls, sealing a military alliance between Portugal and England. It follows the fortress-like architecture built for siege rather than ceremony, the Spanish occupation during the War of the Oranges, and the Gothic cloister added a generation later. Look for the thousands of hand-painted tiles lining that cloister, laid in the 1720s over stone built to repel an army.