 The design of the work, which consisted of a military construction, was entrusted to the Italian-Sienese military engineer, Tiburzio Spannocchi.He constructed a set of habitat attached to the south and east walls that hid the ultrasemicircular turrets in its interior, although in the east façade it did not affect those who flanked the entrance door and these onwards.Surrounding the entire building, a marlon wall was erected leaving inside a round space and ending at its four corners in four pentagonal bastions, whose starts can be seen today.