The castle is built directly on a rocky outcropping at many points, and is universally known for its octagonal shape. On each of the eight edges are grafted eight towers of the same shape in curtain walls in local limestone, marked by a frame open spandrel eight monòfore in the lower floor, seven Windows and one mullioned window, facing the top one in Andria.
The courtyard, octagonal in shape, is characterized as the whole building, from colour contrast arising out of the use of gap reef, limestone and marble; at one time there were also ancient sculptures, of which only slab depicting the procession of the Knights and a fragment of anthropomorphic figure.
At the upper floor there are three doors, under which some elements are present and jutting some holes, perhaps intended to hold a wooden balcony to make independent from one another, all rooms interconnected with a ring path, except the first and the eighth, separated by a wall that opens at the top, a big òculo probably used to communicate.
The sixteen rooms, eight for each plan, have a trapezoidal shape and were covered with an ingenious solution. Space is allocated, in fact, a central span covered vaulted ceiling crocièra square (with semi in brèccia reef ground floor and pillars of marble trilobati to the upper one), while the remaining triangular spaces are covered by ogival vaults.
The keystones of cruises are different, decorated with Zoomorphic and anthropomorphic elements, fitomorfi.
The connection between the two levels is via three spiral staircases in different towers.
Some of these towers hold tanks for rainwater collection, partly conveyed towards the cistern also dug into the rock below the central courtyard. In other towers are located, bathrooms equipped with washbasin and latrine, and joined the
all from a small environment, probably used as a dressing room or perhaps intended to accept ablution pools, since the body was much practiced by Frederick II and his court, according to a custom typical of the Arab world so loved by the sovereign.
Great interest is the sculptural trousseau which, although heavily depleted, provides a significant testimony of the original decoration, a time characterized by the wide range of colours of materials
employees: mosaic tiles, majolica tiles, glass pastes and murals, of which between the late ' 700 and the first of some 800 writers and local historians saw tracks, describing in their works.
Currently there are still the two anthropomorphic shelves in Falconer's Tower, which support the time telamons umbrella of a scalar towers and a fragment of the mosaic in the eighth ground floor room. In the Pinacoteca Provinciale di Bari were temporarily settled, however, two important sculptural fragments, depicting a head and a headless Bust, discovered during restoration, which long have not returned any trace, however, of octagonal tub in the middle of the courtyard, cited by some scholars of the past century.