Le pavillon de l'Audience, Villandry.
A little quick internet research reveals that it was built by the then-proprietor of the castle, the Marquis de Castellane. He used the building as a place to receive (give audience to) the farmers and other people who worked the lands around the castle and town. I guess allowing the peasantry into the château itself was out of the question. According to what I read, the building was completely renovated in 2004.