The State Forest of Eawy, in the Pays de Bray, is one of the largest beech forests in France. It extends over the slopes and the chalky plateau that separate the Varenne and Béthune valleys over almost 17,297 acres (7,000 ha). Formed of an old oak grove until the 16th century, it was then planted with beeches (Fagus sylvatica), some of which today reach almost 98 ft (30 m). A rectilinear breakthrough, paved for 16th-century carriages and named Allée des Limousins, crosses it for nine miles (14 km).