Medieval Castelo de Beja is located in the northwestern part of the city, on a hill and visible from afar.

The castle was built in the XIII century, during the reign of king Dinis, on the ruins of Roman and later Moorish fortifications. The castle was built simultaneously with the city walls and was surrounded by a crenellated wall, and at each corner stood a square tower. Inside, right in the middle was watchtower dungeon, Torri di Menagen, built of granite and marble. The height of the tower Torri di Menagen – 40 meters and is the highest watchtower in Portugal, as well as a magnificent example of medieval architecture. The prongs hinged loopholes Torri di Menagen – small pyramids. Also preserved Romanesque arch, which stands on stone slabs. To get to the top of a guard tower, which offers incredible views of the city and to the plains, you have to climb the spiral staircase, which has 197 steps. On the way up visitors pass through three rooms with Windows in Gothic style. Attracts the attention of the ceiling of rooms, made in the form of an arch with rolling elements of the Gothic style. Currently the castle houses a small military Museum.

Near the castle are the ruins of the city walls. The once tall and strong city walls were crowned with 40 towers and had five gates. From 16 June 1910 Beja castle is classified as a national monument of Portugal.