The exact building date of Castel Gavone ('Castrum Govonis'), the former seat of the Del Carretto Marquisses, is still unknown. The castle rises on a huge, steep curvilinear rampart on top of the Becchignolo hill.
The castle was allegedly built by Enrico II in 1181 on remains of previous defensive structures. It was certainly fortified in 1292. Destroyed during the struggles with Genoa, it was rebuilt by Giovanni I in 1451-1452, along with the Borgo walls.
It underwent further modifications until 1715 when it was largely dismantled by the Genoese who wanted to destroy the symbol of their ancient enemy after their conquest of the Marquisate. Only some of the retaining side-walls were spared in addition to the very famous Diamond Tower (today the best-preserved structure). The Tower, which has a curved triangular base, was built using diamond-faceted squared stones. It faces south with its acute edge resembling the bow of a ship. It is an excellent example of late medieval military architecture. Many of the original materials such as beams, stones and columns, were later used to build churches, gates and houses.
References:Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).