In Assassin's Creed Unity, the Café Théâtre contains the opening Assassin headquarters in Paris.
Arno Dorian uses the Café Théâtre as a base after joining the Brotherhood during the French Revolution. The building is located in the Île Saint-Louis district and can be renovated through optional activities. Improvements provide income and unlock additional functions, making the headquarters part of the game's progression rather than simply a mission backdrop.
Notre-Dame, the Louvre, and Versailles are all recognizable locations in Unity, but they are not the headquarters. Notre-Dame is a major landmark and mission setting, while the Louvre and Versailles appear as important historical locations connected with the revolutionary-era story.
Unity is set mainly in Paris from 1789 onward. Its crowded streets, political upheaval, and period architecture support both solo missions and cooperative missions. The Café Théâtre also reflects the series' recurring idea that an Assassin base can be a social or public place hidden in plain sight.