Castel del Monte (Puglia)

Rising alone from a hill in the Murge plateau, Castel del Monte is a 13th-century castle commissioned by Holy Roman Emperor Frederick II of Hohenstaufen that defies easy architectural classification. The plan is a perfect octagon with octagonal towers at each corner, executed in pale limestone with pointed Gothic entrance arches and interior rooms decorated with colored marble and carved capitals drawing from Roman, Islamic, and northern Gothic sources. No moat, no stables, and no clear defensive purpose have led scholars to propose it was designed as a ceremonial hunting lodge or astronomical instrument.