El Camino Real (Spanish; literally The Royal Road, sometimes translated as The King's Highway) is a 600-mile (965-kilometer) commemorative route connecting the 21 Spanish missions in California (formerly the region Alta California in the Spanish Empire) from Mission San Diego de Alcalá in San Diego to Mission San Francisco Solano in Sonoma, along with a number of sub-missions, four presidios, and three pueblos. The route is historically associated with a network of royal roads (caminos reales) used by inhabitants of New Spain. The modern commemorative route in the U.S. state of California is named after these roads, and is officially defined in the California Streets and Highways Code to run along various roads from Interstate 5 at the Mexican border to State Route 12 in Sonoma.
During the period of Spanish rule, there was no single road constructed by the Spanish to connect the missions, with most of the network of royal roads following historic Native American trading routes. These various caminos reales covered much of what is today California, but with no single special route designated to link the missions. The name was revived in the American era in connection with the boosterism associated with the Mission Revival movement of the early 20th century. Streets throughout California bear the "El Camino Real" name. The route has been continually upgraded and is decorated with commemorative bell markers.