Abaskun, first recorded by بطلیموس as Socanaa, was documented in Arab sources as "the most famous port of the Khazarian Sea". It was situated within three days' journey from گرگان. The southern part of the Caspian Sea was known as the "Sea of Abaskun". See: B.N. Zakhoder (1898–1960). The Caspian Compilation of Records about Eastern Europe (online version).
