The Castrovin Sea is a large, land-locked body of water, which begins near the ancient realm of Iobaria in northwestern Casmaron, and stretches thousands of miles eastward. It borders the lost kingdoms of Ninshabur, Kaskkari, and Iblydos in its southwestern reaches, the mighty Kelesh Empire to the south, and fabulous Kaladay to the east. At least in its northwestern regions, the Castrovin is harsh and choppy, making it difficult to navigate. Sea traffic is generally limited to small fishing vessels which stay close to the coastline. The Castrovin Sea has a generally tempering effect on the climate of Casmaron, increasing rainfall and moderating temperatures along its shores.