Mont Lassois, Hallstatt hillfort and church hill in Vix, Bourgogne, France

Mont Lassois is a hill near Châtillon-sur-Seine with two parts: the higher Mont Saint-Marcel, reaching 306.4 m, and the lower Mont Roussillon. The J-shaped hill rises about 100 m above the Seine valley, with wooded slopes and a 12th-century church, Saint-Marcel, at the junction of the two branches.

The hilltop settlement began in the 6th century before Christ and served as a center controlling trade routes. The community eventually ended, but the remains show it was a wealthy and influential place during its time.

The site reflects a wealthy Celtic community that maintained trade connections with the Mediterranean world. Visitors can observe recovered pottery and jewelry in local museums that reveal the daily life and prosperity of this ancient society.

The site offers walking paths over and around the hills with various viewpoints to explore. Sturdy footwear is recommended as the terrain can be uneven and some areas are exposed.

In 1953 a princely tomb was found containing a dismantled wagon and precious metalwork, revealing the craftsmanship skills of its people. This discovery helped archaeologists understand how powerful and wealthy the leaders of this early community were.