The Alcobaça Monastery is a historic Cistercian monastery located in Alcobaça, Portugal. Founded in 1153, it is one of the earliest Gothic structures in the country and is recognized for its impressive architecture and rich history. The monastery was built to honor the Virgin Mary and served as a significant religious center during the Middle Ages. The monastery is famous for its beautiful church, which features a stunning altar and intricate tombs, including those of Pedro I of Portugal and Inês de Castro. In 1989, the Alcobaça Monastery was designated a UNESCO World Heritage Site, highlighting its cultural and historical importance.