North of the bustling trade hubs of Prand and Rensa City-States, beyond the "Great Cross Trade Route," a cold breath eternally hovers over the waters known as the "Chill Sea." Under the influence of this seemingly everlasting mysterious cold air, the entire Chill Sea displays a distinct appearance unlike anywhere else.
Here, the seawater has a deep, profound texture that sharply contrasts with that of warmer seas, with bits of broken ice often appearing at the junctions of currents and islands. Mysterious large icebergs periodically rise from below the sea surface, forming temporary barriers or moving landmasses that serve as markers or emergency shelters for some sailors making a living in the Chill Sea. Various mysterious phenomena, such as cold mists, icy winds, and phantom lights, are characteristic landscapes of this cold region, giving rise to countless queer legends that have shrouded the two major City-States of Frost and Cold Harbor in layers of mystique.