Tijuana is the largest city in the state of Baja California located on the northwestern Pacific Coast of Mexico. Tijuana is the municipal seat of the Tijuana Municipality and the hub of the Tijuana metropolitan area. It has a close proximity to the Mexico–United States border, which is part of the San Diego-Tijuana metro area.

The Californias, occasionally known as The Three Californias or Two Californias, are a region of North America spanning the United States and Mexico, consisting of the U.S. state of California and the Mexican states of Baja California and Baja California Sur. Historically, the term Californias was used to define the vast northwestern region of Spanish America, as the Province of the Californias, and later as a collective term for Alta California and the Baja California Peninsula.