Chateau des Clées is located above the village. Built probably in the 11th century, it guarded the traffic through the Jougne Pass and collected tolls on the pass road. Les Clées is first mentioned in 1134 when Pope Innocent II tried in vain to prohibit the reconstruction of the castle.
The chapel of Les Clées was built before the 14th century and rebuilt in 1738-1740.
In 1444 the Duke Louis I of Savoy commissioned the renovations of the walls. During the Burgundian War, on 22 October 1475, Swiss Confederation troops seized and destroyed the city and castle and killed the castle garrison. Under Bernese rule there were three courts in the Les Clées district, one of which was held in the city. Nevertheless, the city gradually lost importance.
Today Les Clées Castle with the surrounding ruins and village is listed as a Swiss heritage site of national significance.
Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).