Brownsville–Matamoros

Matamoros–Brownsville, also known as Brownsville–Matamoros, or simply as the Borderplex, is one of the six transborder agglomerations along the Mexico–United States border. It is part of the Lower Rio Grande Valley region. The city of Matamoros is situated in the Mexican state of Tamaulipas, on the south bank of the Rio Grande, while the city of Brownsville is located in the U.S. state of Texas, directly north across the bank of the Rio Grande. The Matamoros–Brownsville area is connected by four international bridges. In addition, this transnational conurbation area has a population of 1,136,995, making it the fourth-largest metropolitan area on the Mexico-U.S. border.

The area of Matamoros–Brownsville lies among the top-10 fastest-growing urban areas in the United States. The Brownsville–Harlingen and the Brownsville–Harlingen–Raymondville metropolitan areas are included in the official countdown of this transnational conurbation.