Perched on a rocky spur, the châtelet of Marbais seems to watch over the Thyle valley and its surroundings. Built at the confluence of two rivers, the Thyle and the Ri des Goutailles, the location is ideal. Rocks and marshes form a natural and effective protection against the enemy, while the rivers are an inexhaustible source of water.
The lords of Marbais chose this small fortification as their home for almost 500 years. The original keep was gradually incorporated into a larger structure and protected by towers, ramparts and a drawbridge. In 1600, when the line of the Lords of Marbais died out, the castle passed into the hands of neighbouring lords, the T’Serclaes de Tilly. Gradually, the castle was transformed into a farm and lost its political role. The keep then served as a stable and granary, and the chapel as a stall.