aerial top down view of alcacer do sal medieval hilltop castle above the sado river in portugal with square towers, palace

walls views undefined trip travel town towers tourist tourism sunset sunrise stunning strategic site sightseeing scenic sal sado ruins roman river reconquista ramparts pousada portuguese portugal picturesque period peninsula panoramic museum moorish monument medieval location landmark islamic iberian hotel history historical historic heritage gatehouse fortress fortified fortification exploration experience empire dungeons discovery defense day cultural conquest civilizations cisterns christian chapels cer castle battlements attraction architecture archaeological ancient alentejo alcaiexcl