The Monastery of Santa Maria de Alcobaça is a historic Cistercian monastery located in Alcobaça, Portugal. Founded in 1153, it is one of the earliest Gothic structures in the country and was built to honor the Virgin Mary. The monastery is renowned for its impressive architecture, including a stunning church and beautiful cloisters. In 1989, the monastery was designated a UNESCO World Heritage Site due to its cultural significance and well-preserved state. It houses the tombs of the famous Portuguese royal couple, Pedro I of Portugal and Inês de Castro, which are notable attractions for visitors.