The isthmus of Tehuantepec. It is also the narrowest stretch of land between the Gulf of Mexico and the Pacific Ocean in Mexico.
The Atlantic Ocean.
The Pacific Ocean qualifies as the ocean separating Japan and Western Mexico.
There is no famous strait between Spain and Mexico, there is an ocean between the two countries, the Atlantic Ocean.
Think atlantic ocean is between mexico and morocco.
Caribbean Sea
there happens to be an ocean between them.
It lies between the United States and Central America, and between the Gulf of Mexico and the Pacific Ocean.
the Pacific
The Atlantic Ocean
Between the Atlantic and the Pacific Oceans. The Gulf of Mexico and Caribbean Sea, which touch Mexico, are considered part of the Atlantic.
I believe you are talking about the easternlowlands that runs across the Atlantic Ocean and the Gulf Of Mexico.