Square spiral staircases appear in Sicily during the 16th century in different contexts and for different purposes. This contribution focuses on two case studies at the “opposite poles” of a casuistry that shares the common characteristics of suspended ramps revolving within a square masonry box around a central void. By analysing these cases we find a probable link with models from Spain. At the same time, they demonstrate a common descent from a constructive culture rooted in the Spanish and Mediterranean stereotomic experience of the early modern age.