Before castles became houses to live in they were war machines, and here you see it because the place is a ruin: a square tower in the middle, a long curtain wall enclosing the service buildings, and empty air below. It stands on a rocky spur at almost eight hundred metres, and from there it controlled the valley floor from Aosta to Saint-Vincent.
What to see
The type is what in the Aosta valley is called a primitive castle: no elegance, no large windows, just the tower and the wall. Walking inside the walls you read the plan without needing signs, because roofs and floors are gone and the skeleton remains.
Within the enclosure is the chapel, which keeps traces of medieval frescoes: it was the church of the garrison and of the people who lived around it. Below, the slope drops onto the vineyards of Chambave, and the position explains everything: whoever held this rock controlled whoever passed through the valley, and in those days everyone passed through there.
Visiting
The castle is in the hamlet of Cly, in the commune of Saint-Denis, and you drive to a point and then walk a short path; it is an open-air ruin, access is free and there are no facilities. An hour between the climb and the walk round.
Our editors' tip
Take something to drink and go up in the late afternoon: there is nobody, the sun cuts across the valley and you see, one after another, the other castles on the heights opposite. They were a chain of watch posts that could see each other, and from up here you understand how it worked.