The Castle of Mértola is a well-preserved medieval castle located in the civil parish and municipality of Mértola, in the Portuguese district of Beja.
Wikipedia https://en.wikipedia.org/wiki/Castle_of_Mertola
Address 38 Rua Elias Garcia, Mértola 7750356, Portugal
Coordinates 37°38'17.906" N -7°39'51.828" E