From 1769 to 1823 Spain constructed 21 missions along the California Coast between San Diego and Sonoma. El Camino Real--the King's Highway--is a series of roads from San Diego to San Francisco which connected Spain's missions, 3 pueblos (or towns located in LA, San Jose, & Santa Cruz plus a 4th established by Mexico in Sonoma), & 4 presidios (at San Diego, Santa Barbara, Monterey, and San Francisco) along the California coast. The first outpost on this trail--San Diego--was established in 1769 while the final mission at Sonoma was completed in 1823.
The missions were religious centers, run by a priest, for the purpose of converting the native population to Christianity. The presidios' main function was a strategic military fortification and barracks, primarily to prevent competing colonial claims from Britain or Russia along the California Coast. The pueblos were designed as towns to provide food & other support to the military presidios. The last piece of the intricate colonial structure of the Spanish was the ranchos which consisted of some 800 private plots of land land used for farming.
After Mexico took over the Spanish region of California in the 1830s the government secularized the missions and sold off their lands. The next 50 years saw many of the missions fall into ruin. In the late 1800s, the US government returned the mission buildings to the Catholic Church, and most have been rebuilt and restored. I have visited all 12 of the missions from San Luis Obispo north to Sonoma, and each is open and welcoming to the public, most with museums and beautiful gardens. While most of the missions offer free admission, some charge just for the museum and a handful charge visitors to view any part of the interior, even the church.


