Urban legend, on the other hand, states that Tía Juana, which means "Aunt Jane" in Spanish, was a real person whose inn provided food and lodging to travelers. The commonly accepted theory among historians is that Tía Juana, as Argüello named his rancho, is derived from the word Tiwan ("by the sea") in the language of the Kumeyaay-the First Nations people of the San Diego-Tijuana region. settlement which is now part of San Ysidro remained Tía Juana until the mid-20th century. While the Mexican city standardized to Tijuana, the American term for both the river and a U.S. The first Spanish mission call the settlement variously as La Tía Juana, Tiguana, Tiuana, Tiwana, Tijuan, Ticuan, as well as Tijuana. The city's name comes from the rancho that Santiago Argüello Moraga established in 1829 on his Mexican land grant, naming it Rancho Tía Juana.
According to the 2015 census, the Tijuana metropolitan area was the fifth-largest in Mexico, with a population of 1,840,710, but rankings vary, the city (locality) itself was 6th largest and the municipality (administrative) 3rd largest nationally.
Tijuana is the 45th largest city in the Americas and is the westernmost city in Mexico. It is estimated that the two border crossing stations between the cities proper of San Diego and Tijuana account for 300,000 daily border crossings alone. This metropolitan crossing makes the San Ysidro Port of Entry the fourth busiest land-border crossing in the world. More than fifty million people cross the border between these two cities every year. The city is the most visited border city in the world sharing a border of about 24 km (15 mi) with its sister city San Diego. Tijuana is also a growing cultural center and has been recognized as an important new cultural mecca. In the early 21st century, Tijuana became the medical-device manufacturing capital of North America.
A dominant manufacturing center of the North American continent, the city maintains facilities of many multinational conglomerate companies.
Tijuana covers 70% of the territory of the municipality and contains 80% of its population. Tijuana is located on the Pacific coast of Baja California, and is the municipal seat and the cultural and commercial center of Tijuana Municipality. As of September 2019, the city of Tijuana had a population of 1,810,645, with its metropolitan area containing a population of 2,157,853 as of 2020, an estimated 2,002,000 within the urban area. Currently one of the fastest-growing metropolitan areas in Mexico, Tijuana is rated as a "High Sufficiency" global city by the Globalization and World Cities Research Network. As the second-largest city in Mexico and center of the 6th-largest metro area in Mexico, Tijuana exerts a strong influence in education and politics, in transportation, culture, art, and manufacturing and as a migration hub. It is part of the San Diego–Tijuana transborder urban agglomeration and the larger Southern California megalopolis. Tijuana ( US: / t iː ˈ( h) w ɑː n ə/ tee- (H)WAH-nə, Spanish: ( listen)) is a city in Baja California, Mexico.