The castle of the Haras National du Pin was built between 1719 and 1724 to serve as the official residence of the successive directors of the stud farm. It was then largely transformed in the 19th century, which marked the clear separation between its different levels, its reception areas, and those dedicated to private life. The ground floor originally comprised two garden apartments accessible by a vestibule and an antechamber replaced by the current castle hall. As for the dining room, it was occupied by a bedroom and a service staircase. The rooms on the ground floor gave way under the Second Empire to ceremonial salons, and the assembly housed in the left wing disappeared while the right wing of the building did not change.