In 1769, the duke of Chartres bought a land of one hectare next to the street of Courcelles. Between 1773 and 1778, he managed to gather a field of 12 hectares after successive purchases. Carmontelle, the designer, set up different points of view and a river. There are evocations of small constructions representing false vestiges of the temple of Mars, a minaret, a Dutch windmill, a naumachie in the oval basin and an Egyptian pyramid! The Parisian called this place "the madness of Chartres."