The remains of the fortress show the feudal occupation of Piène by the Counts of Ventimiglia. The hamlet developed later.
Although the castle has been severely amputated, its remains are still coherent.
This medieval Genoese fortified town (600 m high) is located on a rocky north-south ridge, attached to the east-west ridge of Piène-Haute hamlet by a narrow passage. It overlooks Roya river by 200 meters and enjoys a very wide panorama to the north and south of the Roya Valley.
The medieval well-erected cut stones masonry of the enclosure elegantly draws the site of the old fortress on its rocky site. The door of the outer enclosure is accessible from the church square, to the south, by a narrow passage surrounded by peaks and built on the rock. The route of the rampart, built on the cliff, on the periphery of the site, optimizes the protection created by the existing verticals by pursuing and adapting them. The current height of the remains of the wall, measured inside, does not exceed 2 meters.
A second inner enclosure circles the highest part of the site. A chicane door allow a S-O access. In the heart of the castle, several vaulted rooms and a pool fed by a small cistern are still observable.
The west room is integrated into the outer wall from which it stands as a small tower. The base has an important external fruit. A cord marks the start of the vertical part of the wall.