Burg Pusignan, Medieval castle ruins in Pusignan, France.

The ruins of Château de Pusignan, also called Chastel-Vieil, stand on a moraine hill southwest of the village. A cylindrical tower of stacked tan stone blocks tapers to a flat top, with a small square window high on its left side and the outline of an infilled doorway near the base. Low stone walls and trees surround it.

A Roman camp commanded by Caesar's lieutenant Pusinius stood on the hill before a motte with a wooden tower, later rebuilt in stone as the "Vieux Chatel", was raised in the early Middle Ages. In the 12th century the lords of Moifond built the stone castle with a wide ring wall. In June 1430 the Dauphiné troops took it from an Orangist garrison, and in 1789 revolutionaries burned the site.

The castle played a central role during the Battle of Anthon in 1430, marking a significant moment in the wars between France and Burgundy.

The ruin is located near Lyon-Saint Exupéry Airport and visible from the surrounding plain. Visitors should expect uneven ground and restricted access to the inner structures.

The visible tower is not the 12th-century castle but the remnant of the "Vieux Chatel", the earlier pebble-built structure. Charles VI authorised its demolition in 1389, yet its tapered stone cylinder still stands above the gravel, with an infilled doorway outlined near its base.