The cave was originally called La Grotte de Bellou sur Huisne, after the name of the localcommune in southeastern Orne county, Normandy. It lies in a disused chalk mine used at the time as a mushroom farm. The entrances were walled up, but permission was obtained to gain entry to the labyrinth, referred to by the mushroom workers as 'clay pockets'. It was clear that extensive digging could link up the truncated sections to lengthen the cave from 140 metres to more than one kilometre, making it one of the longest chalk caves. The tunnels are about 1.5 metres high but are extensively choked with sediment.
Exploration
Frenchcavers later renamed the cave and engaged in extensive digging, removing much of the valuable varve deposits which the SCRPLA had hoped to preserve for study by professional soil scientists. The SCRPLA produced a study of the cave which has since been added to by other groups. The cave suffered considerable vandalism when the mushroom farm ceased activity, but has since been re-gated. The cave is not related to any current hydrogeological system. There are very extensive activekarst systems under the nearbyPays d'Ouche district although extensive exploration by the SCRPLA has not managed to penetrate any of these. However, they have located detailed descriptions of at least one cave explored by the Parisian water authorities in the nineteenth century.