El Camino Real (Spanish for The Royal Road, also known as The King's Highway) usually refers to the 600-mile (966-kilometer) California Mission Trail, connecting the former Alta California's 21 missions (along with a number of support sites), 4 presidios, and several pueblos, stretching from Mission San Diego de Alcalá in San Diego in the south to Mission San Francisco Solano in Sonoma in the north.