To the north flows the river Vilaine where there was a pond, swamps and a 30 metres (98 ft) high talus.

The defensive weak point was to the east, in the direction of Laval and the French Kingdom, because access was so easy.

Vitré is located in the Armorican Massif, at the interface of zones of beige sandstone and schist (argillites, black micaceous siltites, locally with ferruginous oolites).

The inventory of the Baronnie de Vitré in 1681 testifies to the presence of springs and fountains in the moat, used by the inhabitants of the districts for laundry, orchards and gardens.

But during the French Wars of Religion, attacks by the Catholic Leagues destroyed a part of the towers and ramparts east of the ancient city.