Castle of Campo Maior

The Castle of Campo Maior is a medieval military fortification, in the civil parish of São João Bapista, municipality of Campo Maior, part of a first line of defense in the Portuguese Alentejo, oriented towards Spain, in conjunction with the military forts of Ouguela, Elvas, Olivença and Juromenha. It is a walled bulwark of the modern era, highlighted by a Renaissance-era window in the northern tower of the castle. It has been listed as a National monument since 1911.

Source: Wikipedia