One of the distinctive features of the bastion was the piazza bassa (lit. “low square”), constructed in the bastion flank, at the point where the bastion abutted the curtain wall. Every landward bastion had two such piazze, built at an intermediate level between the ditch and the scarp. They were protected by the rounded sections at the ends of the bastion faces, which became known as oreillons on account of their resemblance to ear lobes.

The piazze basse were enclosed by merloni, revetted earthworks pierced by a casemate and an embrasure, which allowed for enfilading cannon fire from two different angles in protection of the adjacent bastion, the scarp and the ditch.

Soldiers reached the town and the ditch by means of sortite (sally ports), paved vaulted passages built below the ramparts.