The Gulf of Guinea is the northeastern most part of the tropical Atlantic Ocean. In this Gulf, there happens the intersection of the Equator and the Prime Meridian (zero degree latitude and longitude).
The Isthmus of Kra is located in the Malay Peninsula. It lies between the Ranong and Chumphon provinces of Southern Thailand. It is bordered by the Gulf of Thailand in the east and the Andaman Sea in the west.