The castle stands on top of Monte Pezzulano, at 467 metres, just above the old town: a short path leads up from piazza Conte Rosso. It is one of the oldest in Piedmont, since tradition has it built in 924 by Arduino il Glabro, marquis of Turin, and for centuries it was the last stronghold before Turin for anyone arriving from France. A chronicle written in the mid eleventh century records that marquis Arduino V lived here permanently.
What to see
What remains today are ruins, and it is worth knowing why they mattered. The castle was one of the favourite seats of the counts of Savoy: Umberto III, son of Amedeo III, was born here in 1136, and Amedeo VII, the Red Count, in 1360; here too Philip II of Savoy-Achaea was imprisoned before drowning in the lake below the hill, and here Bona of Savoy was born, future wife of Galeazzo Maria Sforza. Frederick Barbarossa destroyed it along with the villages of Ferronia and Pagliarino, and Thomas I of Savoy rebuilt it. After the fifteenth century, once the court's glory days were over, it stayed on as a valley fortress: the last rebuilding was by Amedeo di Castellamonte, and in May 1691 the French troops of marshal Catinat blew it up with mines. It was never raised again, because the defence of the valley had by then moved to the new Savoy forts.
Visiting
The path from the centre is short but steep, and calls for decent shoes. What you come for is not the architecture, reduced to walls and foundations, but the vantage point: from up there you see the Lago Grande, the morainic hill of Rivoli and, on the ridge opposite, the Sacra di San Michele. It is the same view the castellans had while they watched the mouth of the valley.
Our editors' tip
Come up towards evening, when the light catches the lakes side on. And bear in mind that a fair collection of legends circles these ruins: the chest of French officers' pay buried in the copse to the right of the entrance, the boulder with an arrow supposedly pointing the way to it, and the ghost of Philip II said to hover over the water.