The third level appears in its present state in the form of a terrace, surrounded by the thick perimeter masonry of the tower to perform the function of a parapet. This situation seems to have been produced by a partial collapse of the third elevation – for causes not yet known – that, although with a smaller vertical development than the two below, must also have been constituted by a room covered by a vault. This would fully justify the continuation of the perimeter masonry, maintaining the thickness of the part below. Scarfed to it, on the inside, you can still see the portions closest to the impost of four groins on corbels, directed according to the cardinal points. A fascinating reconstruction hypothesis for the ceiling of this third room proposed a dome with a central oculus, around which there would be joined the four groins protruding from the intrados; the recent identification among the rubbles of a moulded ashlar, identifiable as the crown closing the vault, would seem nevertheless to contradict this hypothesis, at least regarding the presence of the oculus. Inside the thick walls, all the way up the building, a cylindrical space is hewn out, little more than 2 metres in diameter, which houses the only system of connection between the three levels. The original helicoid staircase inserted there, surely in bare stone, unfortunately was demolished in the second half of the 18th century, and today is replaced by an analogous structure in concrete done during the twentieth-century restoration work. In the absence of documentary sources coeval with the construction, reliable old descriptions or imagery sources preceding the demolition of the staircase, we are not able to specify the characteristics of the latter, or to establish its exact typology; the reduced size of the room that contained it and the general sobriety and stringency of the building favour the hypothesis of a simple winding staircase with a central cylinder and smooth intrados, although the example of Maniace Castle in Syracuse also makes more refined and complex solutions plausible. The staircase space closes at the top with an interesting stereotomic solution: a small stone dome formed by concentric rings arranged to form a stepwise intrados, with a small central oculus for illumination and airing. The location of the staircase is indicated on the outside by a vertical sequence of seven small loophole windows. The system of apertures also includes a small portal, currently the only entrance to the tower, and small single-light windows on the first level; two big windows with architraves, surmounted on the outside by lively frames with batons folded at right angles, open up on two opposite sides of the second level, underlining its importance. This is considered by many the fruit of a fifteenth-century “modernization”, but a more convincing thesis takes these interesting windows back to the thirteenth-century building, as the only element that on the outside contradicts the military look of the tower, highlighting its residential function. As Giuseppe Bellafiore points out, analogous motifs also appear at Castel del Monte, so that it belongs to a more general repertoire of forms proper to Swabian architecture.