Grande Pierre de Jouy

The menhir measures 10 feet (3 meters) in length with a width ranging from 8.4 feet (2.55 meters) at the base to 3 feet (0.90 meters) at the top. The stone varies in thickness from 20 inches to 8 inches (50 to 20 centimeters) along its surface. Composed of soft sandstone from local geological formations, the structure now lies completely on the ground after falling from its originally inclined position.

Amédée de Caix de Saint-Aymour documented the structure in 1874, describing its inclined position before it later fell completely to the ground. The precise circumstances of its erection during the Neolithic period remain unknown, though archaeological analysis suggests construction several thousand years ago. The monument received classification as a historical landmark to ensure its preservation for future generations and continued study.

This sandstone megalith provides evidence of human settlements and construction techniques during the Neolithic period in Île-de-France. The monument represents one of the few preserved testimonies from this era in the region, documenting the technical abilities of early communities. Its preservation allows researchers to study prehistoric occupation of the Oise valley and the potential ritual or social functions of such structures during the Stone Age.

The site sits on a hillside at 66 feet (20 meters) altitude along the right bank of the Oise River, accessible via Les Grandes Pierres street. Visits are possible year-round as the monument stands in the open air. Visitors should wear sturdy footwear as the terrain may be uneven. The nearest public transportation options are in Jouy-le-Moutier, approximately 1.2 miles (2 kilometers) from the location.

The use of soft sandstone proves unusual, as most megaliths were crafted from harder rock to ensure stability. The variable thickness may indicate natural erosion or deliberate shaping by Neolithic builders. Geologists have determined the material likely originated from quarries in close proximity to the site, shedding light on the builders' transportation methods and their selection criteria for materials available in the immediate environment.