The 13th century castle and walled city, with a strong Islamic history, overlooking the Guadiana River, Mertola, Alentejo, Portugal, Europe

travel destination tourist destination photography colour image colour horizontal outdoors outside day daytime river 13th century castle walled city islamic history historical heritage historical landmark guadiana river mertola alentejo portugal europe european no people nobody no one no one water building building exterior architecture architectural castle fortified wall protection defence national landmark landmark place of interest white hill the past