Port and city (pop., 2000: 295,442), southeastern Tamaulipas state, northeastern Mexico.
It lies on the Pánuco River and is almost surrounded by swampland and lagoons. It grew around a Franciscan monastery founded с 1532. Destroyed by pirates in 1683, it was not resettled until 1823. It was occupied briefly by U.S. troops (1846) during the Mexican War and by the French in 1862. Until 1901 it was a second-rate port with a reputation for unsanitary conditions. It grew with the rapid exploitation of surrounding petroleum resources to become the most modern port in Mexico and one of the country's leading seaports. It is also a seaside resort.