The Eastern Ocean is the vast expanse of ocean to the east of Sapience. Within it are places like the isle of Ulangi, the pirate port of Mysia, the island temple of Oneiros, and, deep below the waves on the edge of the continental shelf, the meric city of Riparium. The waters are watched over by the ocean spirit Eusia, Guardian of the Eastern Sea. After her, the merfolk have referred to this ocean as the "Eusian Sea."