La Bâtiaz Castle sits on a rocky promontory above the town, its circular tower visible for miles around. The castle was built by the bishops of Sion in the 13th century to control the vital crossroads where the Rhône bends north and the route to the Grand St Bernard Pass branches off. It was repeatedly attacked, partially destroyed, and rebuilt before being abandoned in the 17th century.
Today only the tower survives intact, but it is well worth visiting. The climb to the top offers a panorama of the Rhône Valley, Martigny below, the vineyards of the Valais, and the peaks enclosing the valley on three sides. The surrounding park is pleasant for a picnic. Open in summer only; check locally for current opening hours.