Rosarito Beach Municipality in the context of Rosarito (Baja California)

32°32′31.87″N 117°01′46.63″W / 32.5421861°N 117.0296194°W / 32.5421861; -117.0296194

San Diego–Tijuana is an international transborder agglomeration, straddling the border of the adjacent North American coastal cities of San Diego, California, United States, and Tijuana, Baja California, Mexico. The 2020 population of the region was 5,456,577, making it the largest bi-national conurbation shared between the United States and Mexico, and the second-largest shared between the US and another country. The conurbation consists of San Diego County, (2020 population 3,298,634) in the United States and the municipalities of Tijuana (2020 pop. 1,922,523), Rosarito Beach (126,980), and Tecate (108,440) in Mexico. It is the third-most populous region in the California–Baja California region, smaller only than the metropolitan areas of Greater Los Angeles and the San Francisco Bay Area.

Tijuana Municipality is a municipality in the Mexican state of Baja California. Its municipal seat is located in the city of Tijuana. According to the 2020 census, the municipality had a population of 1,922,523. Montserrat Caballero of the MORENA is the current mayor. The municipality comprises the largest part of the Tijuana metropolitan area.

Tijuana is bordered to the south by the municipalities of Rosarito Beach and Ensenada; to the east, by the municipality of Tecate; to the west, by the Pacific Ocean; and to the north, by the international border with the United States, specifically the County of San Diego, California. The area of the municipality of Tijuana is 879.2 km² (339.46 sq mi); the municipality includes part of the Coronado Islands, located off the coast of the municipality in the Pacific Ocean.