La Mothe Castle, Medieval castle in Arvier, Italy

La Mothe Castle consists of a square tower with a ruined, hollowed-out building attached, whose present form André Zanotto dates to transformations around the 14th–15th centuries. Traces of a round tower and the old perimeter wall remain. Inside, visitors can see the remains of a fireplace with its two jambs and mantel, and traces of frescoes that suggest a chapel.

The castle is first documented in 1287, when Aymon d'Arvier paid feudal homage. According to historian Jean-Baptiste de Tillier, the Savoyard noble Aymar de La Mothe, secretary to Count Philip of Savoy, married the d'Arvier heiress at the end of the 13th century and gave the building his name. In 1306 or 1409 it passed to the d'Avise, then to the Sarriod de la Tour and the Lostan; it was already largely in ruins by the early 18th century.

The name comes from the Savoyard noble Aymar de La Mothe, secretary to Count Philip of Savoy, who married the heiress of the De Arverio family at the end of the 13th century and gave the castle his own name. In the 14th and 15th centuries the d'Avise held it as a maison de plaisance, a pleasure residence, and traces of frescoes found by restorers suggest a chapel, as in neighbouring castles.

The castle is closed to visitors; only the inner garden was opened for free visits in the two decades after the 2006 restoration and safety works, with occasional events held there. A museum conversion project began in 2026, so access may change. The ruins stand in the centre of Arvier, the village itself, not at the entrance of Valgrisenche where Montmayeur Castle lies.

The castle's name comes from Aymar de La Mothe, secretary to Count Philip of Savoy, who married the heiress of the De Arverio family at the end of the 13th century and gave the building his own name. Restorers also found traces of frescoes, suggesting a chapel once stood here, as in neighbouring castles.