The two countries that border the Gulf of Mexico are ; USA and Mexico. And The Peninsula in SE Mexico is the Yucatan Peninsula
The Yucatan peninsula extends from the main body of Mexico into the Gulf of Mexico. To a certain extent, the nations of Belize and Guatemala are part of this peninsula.
The Yucatan Peninsula.
The Gulf of Mexico to the north and west; the Caribbean Sea to the east.
The Yucatán Peninsula separates the Gulf of Mexico from the Caribbean Sea via the Yucatán Channel between Mexico and Cuba.
Yucatan
Yucatan
No. The Gulf of Mexico separates the Yucatan Peninsula (a large, triangular peninsula opposite to the Florida Peninsula) from mainland Mexico.The Gulf of California (also known as Sea of Cortes) is the actual body of water that separates the thin but large Baja California Peninsula from mainland Mexico.
Probably the Florida peninsula but the Yucatán Peninsula is a close contender.
The Gulf of California is the largest gulf off Mexico's western coast. It is formed by Mexico and the Baja Peninsula.
Yucatan Peninsula.
The Gulf of California separates the Baja California Peninsula from most of the rest of Mexico. Note that the peninsula is NOT part of the US state of California. It is part of Mexico.