- The Ship Canal Lower Loire
- The Ship Canal Lower Loire 15 km on a landscaped water line is an important heritage with hydraulic locks and plant (machinery) in the country of Retz on the town of Frossay, the site of the Martiniere the site of the book through the website of New Fields, lateral to the Loire. Built from 1882 to 1892 workers by 1200, he saved the port of Nantes in the 19th century, the Loire and silted up leaving no boats. The channel is now the regulator of water levels in the marshes of the Gulf of Held, the basin and Lake Grandlieu and Bay Bourgneuf.
- Guided tour of the canal by the cultural association of the Ship Canal Lower Loire.