This castle was built around 1250 by Frederick II of Swabia. It has an octagonal plant with eight towers, also with octagonal shape, placed at the eight corners of external perimeter and an internal octagonal courtyard. The number "eight" is its peculiar character, the same eight which when orizontally lies is the mathematical symbol of "infinity". It dominates the Apulia from top of a hill and for this reason it has been named "Crown of Apulia". None knows what was its destination: someone says a castel for hunting, other an astronomical observatory. Certainly now it is the “pearl” of Apulia, well placed on its head, and with its "magical" shape shows to all mankind the power of the emperor Frederick II. The pictures show some views of this great masterpiece of medieval architecture, from 1996 inserted in the list of UNESCO monuments. The castle has two floors: the second one has eight rooms each with a single window looking toward the hills surrounding. This photo, taken inside the castle, shows the internal courtyard: the "magical eight” reaches its perfection in the eight sides of the octagonal shape. This story ends here, but I hope that it has been interesting and to have the time to make a story with the others pictures taken of this marvelous example of medieval architecture. Thanks to all.