Magnus Sinus
δ μέγας κόλπος
Magnus Sinus (δ μέγας κόλπος, Ptol. 7.2. §§ 3, 5; Agathem. i. p. 53), the great gulf which runs up to the middle of the present kingdom of Ava, and is known by the name of the Gulf of Siam. The ancient geographers correctly placed China on the east of this gulf, though they had no very accurate notions relative to its latitude or longitude. On the west side was the Aurea Chersonesus.
From William Smith (ed.), Dictionary of Greek and Roman Geography. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.