This museum of social anthropology has presented since opening in 1995 material witnesses to traditional society in the North East of the Seine-et-Marne, as well as municipal collections on Pierre Mac Orlan (1882-1970), a writer of "social fantasy", who lived for about forty years in Saint-Cyr-sur-Morin.

In the old inn, “La Moderne” (a building that has been completely reconstructed and extended with a modern wing), a permanent exhibition evokes agriculture, breeding, village and semi urban crafts, the use of raw materials and the rural habitat in a sector heavily affected by the urban expansion of Marne-La Vallée.