Château-Neuf d'Allinges, Medieval castle ruins in Allinges, France.

Château-Neuf d'Allinges is a ruined castle on the western side of the butte des châteaux, a hill rising to 712 metres. Its remains include a tall cylindrical tower with a dark conical roof, a long curtain wall of rough grey and tan stone, a castle chapel, two barbicans defending the south-west approaches, and a barn with vaulted cellars. The walled bourg that once accompanied it has left few traces.

The castle was founded in the 10th century and served for centuries as an administrative center of the Chablais region. It experienced significant upheaval during the religious conflicts of the 16th century.

From September 1594 to March 1595 Saint Francis de Sales stayed at the castle as a guest of Baron d'Hermance. Each day he walked down the hill to preach in Thonon and the surrounding area, working to bring the population back to the Catholic Church after the Bernese occupation had turned it to the Reformation. The Missionaries of Saint-François-de-Sales, owners since 1832, still occupy the former lodgings.

The ruins are reached on foot from the hamlet of Mâcheron to the south, via the avenue des Châteaux, or from Allinges to the north, via the rue d'En-Haut. The two castles stand 150 m apart on the butte des châteaux, separated by a small col cut by two ditches; the climb is steep and the ground uneven.

The two castles stand only 150 metres apart, separated by a small col cut by two ditches. From 1268, after the death of Peter II of Savoy, their garrisons fought for nearly 70 years, and siege engines set up at Allinges-Vieux damaged Château-Neuf in 1291, 1292 and 1302.