Self-guided tour (brochure available from the Mers, Eu and Le Tréport TAOs).Ault and the sunken city.The first inhabitants, fishing sailors, built their thatched cottages on the pebble beach. This area, along with Notre-Dame church and the cemetery, formed the lower village and fishermen's quarter. This position enabled them to be closer to their boats, which were gathered in a 100-meter-long cove: Port Perroir (around 80 boats), a thriving port in the Middle Ages. In 1583, all hell broke loose: a memorable storm ravaged Ault, demolishing the church,