Bellver Castle, Island of Majorca, Balearic Islands, Spain
Bellver Castle is a Gothic style castle on a hill 3 km NW of Palma de Mallorca on the Island of Majorca, Balearic Islands. It was built in the 14th century for King James II of Aragon, and is one of the few circular castles in Europe. Long used as a military prison throughout the 18th to mid-20th century, it is now under civilian control, being one of the main tourist attractions of the island, as well as the seat for the city's History Museum.
References sources : wikipedia