The most important are along the Gulf of Mexico and Caribbean Sea coasts; there are many others near the Desierto del Vizcaino in South Baja California; another important wetland is on the delta of the Colorado River.
The following link has in detail all wetlands known in Mexico:
http://www.ramsar.org/cda/ramsar/display/main/main.jsp?zn=ramsar&cp=1-63-78^18395_4000_0__
Mexico's Gulf lowlands i think
In the tropical lowlands of south-central Mexico, near the modern-day cities of Veracruz and Tabasco.
The Mayan civilization.
The Yucatan peninsula and the lowlands surrounding the Gulf of Mexico.
Gulf Coastal Plains
petrolium, oil, gasoline, the works.
Plantations, also known as plantaciones.
Flat lowlands and peidmonts
Deposits of oil and natural gas.
Most Mexican oil is found along the lowlands and shallow waters of the southern Gulf of Mexico.
Plantain
The lowlands and shallow waters along the southern Gulf of Mexico are where the main deposits of oil and natural gas exist in Mexico.