The Royal City-State of Caerreyn is the capital of Reynland and home to its institutions of government. A massive fortress shaped like a star, protected by magical wards and anti-airship cannons, Caerreyn is nearly impenetrable. In the center of the city is the Queen's Palace, from where Queen Avelina of Caerreyn reigns over Reynland. It also acts as the prime fortress of the Red Reyn and is pimarily populated by that race of Reyn. The city is also home to the Red Reyn's main religious and cultural institution, the Church of the Stars, as well as the nation's primary government-sponsored Mage's Academy. Caerreyn is directly governed by a mayor who serves on the Queen's Council.

The city is located at the bottom of a valley and is ringed by tall ice-capped mountains. The valley floor appears to mostly be grass with a few scattered trees and has a river flowing through it. The city is organized in a shape like a many-pointed star, surrounded by high walls protected by anti-airship cannons. Also on these walls are the docks for both military and commercialairships. In the center is another set of walls also organized like a star that surround the Queen's Palace. The river flows through the city and the palace ground, with large openings in the walls allowing passage of the river.