Castelo do Queijo is a 16th-century castle in Porto. His name can be translated as "cheese castle". This original name is due to the rocks on which the stronghold stands, and which apparently resemble cheese in appearance. The castle was built on a star plan and stands on the very edge of the ocean. It is characterized by nice, semi-circular bastions. It is a military facility, but made available to visitors.
In 1938, the Municipal Committee of Art and Archeology (Comissão Municipal de Arte e Arqueologia) proposed that the fort would be adapted for use as a museum. However, as early as 1943, the war caused anti-aircraft batteries to be installed in the fort to protect against German attacks. In order to raise funds to pay for the permanent guard, the castle was reopened to the public - the fort was then used as a viewpoint.