The Haras National du Pin, the oldest of the French national stud farms, bears witness to innovation in terms of equestrian architecture. This unprecedented royal construction from the beginning of the 18th century has a sober decor yet marked by the architecture of the school of Versailles. It is intended above all to be functional and bases its priority on the accommodation of the horses. The period buildings (stables, castle) are arranged in a horseshoe plan around the main courtyard. Enlargements were made in the 19th century.