Donjon de Broue, Medieval tower in Saint-Sornin, France

The Donjon de Broue is a ruined quadrangular keep, now 25 metres high, on a rocky mound in the Brouage marshes. Its walls of small pale stone blocks are strengthened by flat buttresses, and two narrow vertical openings sit above a larger irregular hole. The top edge is broken, and yellow lichen marks the stone.

A castle at Broue is first mentioned in a 1047 charter, when Geoffroy Martel, son of Foulques Nerra, held it; the keep may be among the oldest in France. In 1372 Bertrand du Guesclin besieged and retook it from the English, freeing Isabelle de Valois. The sires de Pons held it until the early 17th century, then abandoned it as the gulf silted up; by the 18th century Claude Masse's maps show it already ruined.

Broue was a salt-trading port: the lords of Broue drew most of their income from the salt pans, and in 1244 Geoffroy de Doué was fined for failing to maintain his harbour. The settlement once had two churches, Saint-Pierre and Saint-Eutrope, of which nothing remains.

The tower sits in a rural location accessible by local roads and best reached by car. Visitors should plan for walking time to reach the site and check access permissions beforehand.

The tower's four surviving levels once stood about 30 metres high; today they reach 25 metres. It probably served as a landmark for ships crossing the old Gulf of Saintonge, guiding vessels toward the salt port at its base.