The Mexico–United States border is an international boundary running from Tijuana, Baja California, and Imperial Beach, California, in the west to Matamoros, Tamaulipas, and Brownsville, Texas, in the east. The border, separating Mexico and the United States from each other, traverses a variety of terrains, ranging from major urban areas to uninhabitable deserts. It is the most frequently crossed international boundary in the world, with approximately 230,000 (2014 and down by 25,000 from 2013) legal crossings being made each day.