Originally a windmill since 1830, the Beaulieu-sous-la-Roche mill, located in the hamlet of "Les 3 Moulins" (The Three Mills), was converted to steam power by its owner, Jean Emmanuel Trichet, at the beginning of the 20th century.
After his death on June 3, 1916, his children completed the conversion into a flour mill and built the village houses. At that time, nearly 10 workers were employed there daily.
Clovis (1900-1982), the third of Jean Emmanuel's seven sons, received the mill as a gift in 1924 and continued its operation.
The mill was supplied with wheat exclusively from the Vendée region. A dynamic entrepreneur passionate about innovation, Clovis nevertheless had to abandon the mill in 1933 because it was too small to meet the growing demand for flour and, above all, too far from the railway, an increasingly important transportation route. The sale of part of the land and buildings associated with the Beaulieu mill enabled the construction of a modern flour mill, initially powered by fuel oil and later by electricity, located near the Aizenay train station and the main roads leading to the ports of Les Sables d'Olonne and Nantes.
Year after year, all that remained of this Beaulieu venture was the mill tower, encircled by a mantle of undergrowth, brambles, and ivy, resembling a Gothic manor house.
In 2002, Gabrielle Mignen, daughter of Clovis Trichet, bequeathed it to the municipality.
She financially supported the project to restore and convert the mill into a birdwatching and conservation area, under the direction of Mayor Maurice Poissonnet.
He inaugurated it on April 25, 2015.