La Grande Roche, also known as the Grande Roche de la Plématrie, is a cave with archaeological sites located in the commune of Quinçay, Vienne, Nouvelle-Aquitaine.

This cave has delivered an exceptional stratigraphy of Châtelperronien, especially towards the front of the cavity, which forms the most complete series known in France at the end of the twentieth century, covering the Cottés interstage, during the isotopic stage.

The stratigraphy of the cave has a rare feature: the summit of the Châtelperronien (Ejo layer) is sealed by the collapse blocks already mentioned, which excludes any contamination by later levels; moreover, no level of the Upper Paleolithic is present above. In addition, the "E" layer at the base of the excavation is also sealed by similar blocks that exclude any contamination by prior deposits (see above).

It is not possible to determine precisely the evolution of the occupation of the cave after the collapse of the vault because the more recent strata have not been protected; but the cavity continued to be used in the final Upper Paleolithic (lithic industry), in the Mesolithic, in the Neolithic (shards), in the Bronze Age, Gallo-Roman times and the Middle Ages.

The integrity of the critical layers for the Châtelperronian series is thus ensured, with the sealing of the layers of the archaeological interval.