Castel del Monte, Apulia, Italy

© Toni Spagone/Alam

Info. Castel del Monte, Apulia, Italy

Built in the 1240s by the Holy Roman Emperor Frederick II in south-east Italy, Castel del Monte (Castle of the Mount) has an unusual design. Eight stone walls stretch between eight octagonal towers and enclose an octagonal courtyard. Each of the two floors also has eight trapezoidal rooms. Listed as a World Heritage site in 1996, the castle has a blend of classical Roman, Arabic and medieval architecture and design.