Château de Sonnaz, Château in Thonon-les-Bains, France

Château de Sonnaz is a 17th-century building in central Thonon-les-Bains, next to the upper funicular station and overlooking the port of Rives. Its pale grey facade has a steep brown tiled roof with a dormer window, two chimneys, and dark red shutters on the upper floor. A stone entrance with a canopy bears the words "Office de Tourisme" and "Musée du Chablais".

Amédée V of Savoy built a fortified castle here in 1290, on a rise above Lake Geneva, and the first town walls of Thonon went up at the same time. In 1589 troops of Nicolas de Harlay, sieur de Sancy, entered through a traitor named Leclerc and took it after three days; Leclerc was hanged by the Senate of Savoy. A fire in 1616 partly ruined it, and it was razed, its stone reused for the Sainte-Maison and the Ursuline convent.

The Chablais Museum, housed in the château since the town bought the building, keeps a permanent room devoted to Marguerite Peltzer: the sculptor bequeathed the contents of her studio to Thonon-les-Bains in 1991. Two further permanent displays cover smuggling along the border and the lateen-sailed boats of Lake Geneva, including a replica of the Savoie.

The château stands in the centre of Thonon-les-Bains, next to the upper station of the funicular and near the town hall, above the port of Rives. The Musée du Chablais and the tourist office share the building, whose entrance is marked by a stone canopy and the painted sign "Office de Tourisme / Musée du Chablais".

The museum's permanent displays include one on smuggling across the Chablais, whose mountains and lake gave smugglers routes, and another on Lake Geneva boats: from the late 18th to the early 20th century, stone was carried on lateen-sailed boats such as the Savoie, a replica of which is shown.