In the modern imagination, it is often the Romans, rather than mediaeval peoples, who are remembered for their skills in engineering and civic architecture, from their great aqueducts and bridges to their ruler-straight roads. Among the fields of southern France, however, is a reminder of the ingenuity and willpower of the region’s mediaeval residents called the Etang de Montady. In the 12th century, the area was a swampy freshwater wetlands with a lake at the centre. During the following century, however, a series of radially placed drainage canals were installed by monks so that the lake could be emptied and reclaimed for farmland. Today, the edges of this substantial engineering project can be traced by the system of wedge-shaped fields first planted in the Middle Ages that have retained their boundaries until today.