The Ravelin of the Visconti Castle of Locarno (1507)
The Ravelin of the Castle of Locarno is one of the few military remains of the fortified castle, mostly demolished by the confederates in 1532.
This remain, a bulwark with a summit pointing northwards, is characterised by two 90º faces, an east side located at 45º as to the relative face and is divided in sectors: one high such as the face, the other one lower than the half. The walls, about 10m high, are inclined along the 9/10m scarp and vertical in the higher part, where there is a parapet with a cordon between the two sections. Four embrasures are located in the pillbox, two in the north face and two in the east face: three can be seen from outside, but the fourth only in the northern tunnel. From outside, the Ravelin seems irregular and quadrangular, with three sides turned towards the attacker and one adjacent to the medieval castle. The walls are made of pebbles, surely from the Maggia River, and the cordon and salient of carefully moulded stones. The defence of this salient was assured by a scarp and a tunnel for musketries or culverins, where you can also observe a loophole.
The exterior planimetry matches the layout of the interior areas. The pillboxes and the tunnels used by the artilleries are located in the interior perimeter of the Ravelin. You can access them by the northern embrasure, transformed into a portal. Nowadays closed, the northern tunnel surely guided directly inside the castle. An ancient tower is located in the centre of the bulwark. The tunnels are barrel vaulted, which is quite original since for each embrasure there is an air hole for the gunpowder smoke that flows perpendicular from the opencast terrace along the rampart. Another embrasure, located in the thickness of a column that supports vaults, looks like a door with jambs.
A long and complex archivist research established some preliminary data on the bulwark: who built it, for whom and when. People believe that the bulwark was built during the French occupation of Locarno (1499-1513), at that time a village of the Duchy of Milan, also under the power of the French people. In truth, it was built in 1507 by Louis XII from the Valois-Orléans branch, King of France. The purchaser was the “grandmaître” Governor Charles II d’Amboise, Lord of Chaumont. The engineer who designed the bulwark could have been a Master influenced by Florentine and Renaissance archetypes, then still unknown in Milan. He was therefore experienced in models applied by Francesco di Giorgio Martini and by the Sangallo family.
A quinquennial research established that the Ravelin was planned by Leonardo da Vinci. This theory is supported by honourable experts, such as Carlo Pedretti, a worldwide famed researcher of the da Vinci work. Nevertheless, a great work of archaeological excavations and facility studies have to be done, in order to establish the preservation conditions and the morphometry of the building, age by age, area by area.
Marino Viganò, historian and researcher