The experimental site of the fortified castle of Guédelon extends in the heart of the Burgundian forest in the Yonne department, on the territory of the small commune of Treigny, 9.3 miles (15 km) from the village of Saint-Fargeau. It is far from everything and accessible by a winding and often wet road. The castle, invisible from the road, stands in a clearing in an oak forest and is not lit at night. There was no vestige, archaeological trace, nor castle there. The site extends around an old disused quarry (Carrière des Murs) and a water point over an area of around 37 acres (15 ha), to which are added 198 acres (80 ha) of adjoining forest.