Matamoros–Brownsville,[1] also known as Brownsville–Matamoros,[2] or simply as the Borderplex,[3] is one of the six transborder agglomerations along the Mexico–United States border.

[4] 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.

[8] The Brownsville–Harlingen and the Brownsville–Harlingen–Raymondville metropolitan areas are included in the official countdown of this transnational conurbation.

Note: Principal cities are bolded.