 On the final level, protected by a strong curtain wall (around 1200 - 15th century) with cannon embrasures (15th century), stands an imposing rectangular keep built in the 12th century.This construction is partly founded on the walls of the residence, or "domicilium", built by the lord of Lavardin, probably in the 1070s.Reinforced by three strong towers between the end of the 12th century and the 13th century, it was rebuilt by the counts de Vendôme, between the end of the 14th and the middle of the 15th centuries.