By car,
A4 motorway, exit "St Jean les 2 jumeaux", cross the Marne at Sammeron, then direction Lizy sur Ourcq. At the roundabout of the pyramid, direction Meaux. At the first houses on the left, rue de Tancrou. After the speed bump, go down rue Ernest Dollé on the right. The Forge Saint Martin awaits you at number 3.
By train: Near Lizy sur Ourcq station, line P of the transilien linking it to Paris-Est station.