Belem Tower is a fortress constructed over the years 1515 to 1519 in the Belem area of Lisbon. The structure’s official name is Torre de São Vicente (St. Vincent’s Tower). In contrast to its beautiful Manueline exterior, this landmark, also known as “our Lady of the River Tagus,” features a water dungeon constructed underground to hold political prisoners. In 1983, it was placed on the list of UNESCO World Heritage Sites, together with the Monastery of the Hieronymites. Today, its interior serves as a museum.