It houses the Grand Palais, the full-time residence of the monarch of Ataraxia, Queen Marie-France VII. It also houses the appointed Conseil des Sénateurs, once the main legislative and consultative body to the monarch, but now largely ceremonial next to the directly-elected Conseil Populaire de la Fédération.
Ataraxia City is home to the Conseil Populaire, the prime minister and most government ministries, and nearly all foreign embassies, though some countries retain missions and consular buildings in Port-aux-Princes that predate the federation process. Ataraxia City also houses the Petit Palais, built to represent the monarch in the administrative capital after the federation process and the creation of the Conseil Populaire.
Cartelet houses the Royal Court. The Royal Court had historically been based in Port-aux-Princes. While today the Prime Minister names judges to the court with nominal approval by the monarch, judges were historically appointed directly by the monarchy. Relenting to republican criticism, the monarch consented to let the Court leave Port-aux-Princes. The Southern regional government objected to the loss of jobs and prestige and successfully lobbied for the Court to move to a high-rise in the growing CBD of Cartelet, a satellite city of Ataraxia City, in 1995.
Port-aux-Princes is home to the starting line of the most well-known marathon in Ataraxia, the Marathon des Deux Capitales. The marathon starts at Esplanade de la Défense in sight of the Grand Palais and ends at Ataraxia City's Esplanade de la Fédération in sight of the Conseil Populaire, famously using the Tunnel du Midi to cross the Var River. The route symbolizes Ataraxia's transition from an absolute monarchy to a democratic federation