Magnus Sinus

The Magnus Sinus or Sinus Magnus (Latin; Greek: ὀ Μέγας Κόλπος, o Mégas Kólpos), also anglicized as the Great Gulf, was the form of the Gulf of Thailand and South China Sea known to Greek, Roman, Arab, Persian, and Renaissance cartographers before the Age of Discovery. It was then briefly conflated with the Pacific Ocean before disappearing from maps.