Now the UNESCO-recognized centerpiece of Alcobaça, the 12th-century Alcobaça Monastery (Mosteiro de Alcobaça) was one of Portugal’s first Gothic buildings. Highlights include the elaborately tiled Hall of Kings and the stark and simple nave—the longest in Portugal—while the transept houses the tombs of several Portuguese monarchs.

A surprisingly humble interior hides behind the lacy stonework facade, looming gargoyles, and prickly spires of Batalha Monastery (Mosteiro da Batalha), the UNESCO-recognized resting place of Portuguese royalty. Explore the myriad chapels and cloisters, before watching sunlight pool through the statement stained-glass window.