Medieval drainage project shaped Montady’s landscape

The area around Montady, near Béziers, has a unique circular pattern resembling a large cartwheel, with radiating lines converging at a central point. This pattern was created by a medieval drainage project from 1247, led by the archbishop of Narbonne, Guillem de Broue.

Drainage transformed swamp into farmland

The project drained a large pond covering over 400 hectares using more than 120 km of ditches. Water was transported through a 1,400-meter underground gallery under the Ensérune hill, which is still in use today. This effort turned a swampy, unhealthy area into productive agricultural land, mainly vineyards.

Underground system still functions today

The underground gallery, built in the 13th century without modern tools, acts as a natural siphon, allowing water to flow under the hill to a natural outlet. This system continues to drain rainwater and groundwater, keeping the agricultural land usable throughout the year.

Circular pattern visible only from above

The circular layout of the ditches is not visible from the ground but can be seen clearly from above or through satellite images. This unique landscape is one of its kind in Europe, showing how medieval engineering decisions have had a lasting impact on the land’s structure.

Montady reflects broader historical trends in France

Montady’s landscape is part of a larger trend in France where ancient human activity has created unusual landscapes or ecosystems. Similar examples include Lake Der in Champagne, which supports white storks, and the Carrières de Lumières in Baux-de-Provence, former quarries now used for digital art performances. Montady’s history shows how medieval engineering continues to influence the region’s agriculture and geography today.