In Assassin's Creed Unity, Paris is the primary setting during the French Revolution.
The game follows Arno Dorian, an Assassin operating in Paris from the late eighteenth century. Its story unfolds against the French Revolution, beginning in 1789 and continuing through years of political upheaval, violence, and changing power.
Paris is represented through districts, streets, palaces, churches, and crowds. Major landmarks include Notre-Dame, the Louvre, the Tuileries, and the Bastille. These locations support investigation missions, stealth opportunities, and large-scale crowd scenes.
The city should not be confused with Versailles, where Arno spends part of his childhood and where the opening sequence occurs. Versailles is historically connected to the revolutionary period, but Paris is the main playable city and the answer to this question. Unity was also designed around cooperative missions that allow multiple players to explore Paris together.