The Porta Granarolo, situated to the north of the small village of the same name, served to connect the interior of the walls directly with the single large village of Begato. The gateway was not included in the list proposed to the Colleges by Ansaldo De Mari and was probably built later, towards the end of the 17th century, to replace a sortie planned as usual on one side of the rampart. In fact, in Codeviola’s surveys, the exit gallery indicated as Porta di Granarolo was just a simple tunnel ten palms wide (2.48 m) and the new arrangement of the sortie was facilitated by the steep difference in height on the two opposite sides of its flat bastion. Today, as in the past, the gate opens onto a small square facing the “ramparo” and connected to the upper and lower embankments by means of stone stairs, while on the outside it is characterised by a fine round sandstone archway, against which an eighteenth-century coat of arms in white marble contrasts.
In Brusco’s survey, the outer gate was protected not only by the moat, but also by a small wall closed by a gate or a bar like the one described by Giovanni De Medicis, and the access to the moat was interrupted by a double bayonet wall. Today, since the asphalted road to Begato passes much further downhill and penetrates inside the walls through a wide gap, the ancient gate has remained deserted and the old road ends in the countryside half-hidden by brushwood and plants. However, the external passages, the moat and the covered road are still legible, although they have been greatly altered by 19th-century alterations.
Even the inner gallery was enlarged by the Sardinian Military Engineers and a space was created that was perhaps much easier for the guardhouse, but which, created between the old narrow passage and the outer wall of the rampart, made the latter much more vulnerable, divided from the outside by the thickness of a single diaphragm wall rather than the compact one of the embankment.
(Taken from “Le Fortificazioni di Genova” by Leone Carlo Forti)