Rondella delle Boccare, Venetian bastion in Verona, Italy

Rondella delle Boccare is a circular masonry bastion on Verona's left bank of the Adige. Its perimeter wall averages 9.80 metres thick, with a battered profile up to the cordon and a brick facing. Inside, an annular casemate 35.50 metres in diameter surrounds a central cylindrical column 8.70 metres across that supports the ring vault.

Built between 1522 and 1525, this fortification was part of Venice's redesign of Verona's city walls to use gunpowder weapons effectively. The round shape represented a new approach to fortress design to better withstand cannon fire.

The name Boccare likely comes from the wide openings in the casemate vault, made to vent gunpowder smoke, though it may instead refer to the many gun ports in the perimeter wall. The circular casemate, 35.50 metres across, still shows the artillery post and the banquette where riflemen fired behind the parapet.

The entrance portal of the casemate is built of rough-hewn rusticated stone blocks, and the ring-shaped casemate inside measures 35.50 metres across. The upper platform was covered with a layer of rammed earth in the 1840 restoration, and a powder magazine was placed under the earthwork beside the entrance portal.

The central cylindrical pillar is 8.70 metres in diameter and carries the annular vault of the casemate, which spans 35.50 metres. The outer wall averages 9.80 metres in thickness, faced in brick and sloping outward up to the cordon line before rising vertically to the parapet. The severe portal of rough-hewn blocks recalls the fortification ideas of friar Giovanni Giocondo.