Castel del Monte, octagonal castle, built for Emperor Frederick II in the 1240s, UNESCO World Heritage Site, Apulia, Italy, Europe

photography colour colour image color color image horizontal horizontal image outdoors outside day nobody no one no one travel destination travel destinations travel landmark landmarks famous well known well known landscape landscapes tourism castel del monte octagonal shape castle 13th century unesco unesco world heritage site world heritage site apulia italy italian europe european fort forts fortified fortification fortress fortresses building exterior building buildings architecture architectural medieval stone tree grass citadel focus on background background focus geometric wall castle wall