Forte da Ponta da Bandeira

The Fort of Ponta da Bandeira, also known as Pau da Bandeira Fort; Fort of Nossa Senhora da Penha de França; the Fort of Registo; or the Fort of Lagos is situated in the city of Lagos, in the Faro District of Portugal. It was built in the 17th century, as one of the main components of a system of maritime fortifications to defend the city, then headquarters of the military government of the Algarve. Significant restoration work has been carried out over the years and the fort is considered to be one of the best-preserved 17th century fortifications in the Algarve region.

Source: Wikipedia