When the Emper­or Fred­er­ick II built this cas­tle near Bari in the 13th cen­tu­ry, he imbued it with sym­bol­ic sig­nif­i­cance, as reflect­ed in the loca­tion, the math­e­mat­i­cal and astro­nom­i­cal pre­ci­sion of the lay­out and the per­fect­ly reg­u­lar shape. A unique piece of medieval mil­i­tary archi­tec­ture, Cas­tel del Monte is a suc­cess­ful blend of ele­ments from clas­si­cal antiq­ui­ty, the Islam­ic Ori­ent and north Euro­pean Cis­ter­cian Goth­ic.