Ervy-le-Châtel is located at 160 meters of altitude, in the southern confines of the Champagne-Ardenne. It occupies the site of a very old circular strong place of about two hectares called "Pâté" which crowns one of the last buttresses of the massif of the forest of Othe above the valley drained by the Armance.
The heritage is particularly rich since three monuments are classified or inventoried "historical monuments": the church of Saint-Pierre-ès-Links, the Saint-Nicolas gate and the circular market.