Massif de l'Hautil

The Hautil Massif is a forest area located between the Seine and Oise river valleys in the northern Yvelines department. It covers approximately 1,250 hectares with a highest elevation of 185 meters.

Neolithic settlements and Roman fortifications such as Camp de César once existed near the forest boundaries. Later, intensive gypsum mining shaped the area for two centuries until the 1980s.

The sun-facing slopes once held vineyards during the Middle Ages that supplied Paris until the 1800s. Though these vines are gone, the history of wine production remains part of the area's identity.

Marked trails run through the forest, allowing visitors to explore the landscape. Some sections are off-limits due to old underground gypsum quarries, so stick to designated paths for safety.

Beneath the forest lies a network of underground galleries spanning about 200 hectares, evidence of two centuries of gypsum extraction. These abandoned tunnel systems make the area a hidden geological landmark.

Location: Vaux-sur-Seine

Address: massif de l'Hautil, 78740 Vaux-sur-Seine, France

GPS coordinates: 49.00970,1.99389

Latest update: December 12, 2025 07:51