Ebalo II of Challant began building it from scratch in 1343, once a long inheritance dispute finally handed him the fief of Ussel. What went up is the first single-block castle in the Aosta Valley: one plain rectangular volume set on a serpentinite crag, watching both the mouth of the Valtournenche and the floor of the Dora Baltea.
What to see
The south front, the one facing the path up, took all the carving: a row of two-light windows, no two alike in their arches or colonnettes, the finest of the fourteenth century in the valley. The one on the main facade is cut from calcschist, a rock formed on the floor of the Tethys Ocean. A band of blind arcading and battlements runs above; two projecting round turrets and a machicolation guard the door. The north side, sheer above Châtillon, answers with two square turrets and a central keep that works more as a lord's emblem than as a refuge. The walls are thin for the period, and real windows with stone seats sit beside the arrow slits: this was a place to live in, not only to defend. In shape it stands halfway between theatrical Fénis and severe Verrès.
Visiting
Inside, bare rock breaks through and cuts the building from three storeys to two; the monumental fireplaces left their traces, stacked to share a single flue. The castle opens only in summer, for temporary exhibitions. After the death of Francesco di Challant in 1470 it served as a prison, then a barracks, then fell into ruin; the Passerin d'Entrèves took it over in 1846 and gave it to the Region in 1983. The restoration, paid for by baron Bich of Bic pen fame, finished in 1999: a transparent dome now replaces the lost roof and stairs lead up to the wall-walk.
Our editors' tip
You walk up, and the path comes out on the south side, which is the right angle from which to look at it, with the windows in a row. Around the rock you can still spot the entrances of the tunnels where magnetite was mined.