Congratulations to ace traveling sleuths, PortMoresby and TravelRob, for recognizing Mission San Juan Capistrano! That's indeed where Gumbo was. Jonathan L also suggested the Los Angeles Mission, which I've never visited but geographically is just a little over an hour's drive north of this.
While exploring the grounds of Mission San Juan Capistrano -- known as the "Jewel" of the California Missions -- Gumbo came upon this small chapel. It's Serra Church, the oldest church in California, named after Father Junipero Serra who founded this mission (and eight other California missions). Our WITW photo included the "Golden Altar", an early Baroque-style retablo, which is a relatively recent addition to the church. The altar is from Barcelona, handcrafted almost 400 years ago of cherry wood and overlaid in gold leaf. It was installed in the Serra Church sometime between 1922-1924.
Serra Church was built in 1782, six years after Mission San Juan Capistrano was founded (on All Saint's day, November 1, 1776). It was one of the first non-native buildings ever constructed in California, being made of adobe and fired brick by native workmen. It is the spiritual heart of the Mission and has served numerous generations of Catholics in the region.
Father Serra was an interesting man who left a powerful mark on this mission and all of early California. Father Serra left Mexico and headed into California when he was more than 50 years old (at a time when most people didn't live to 40 years) to begin his mission work here. His work required a lot of travel and he spent limited time at each of the missions he founded. But Mission San Juan Capistrano is the only mission with a church named in his honor and Father Serra is known to have celebrated mass in this newly built adobe church in 1783, just a year before he died. It is the only church in which he is known to have officiated and, as mentioned, is the oldest church in the state.
The chapel had fallen into disrepair in the late 19th century but was restored in the early 20th century. It is still actively used to celebrate mass and host weddings, baptisms, and funerals. In 2005, Serra's Church underwent extensive conservation work, completed in 2010. This work included cleaning and conservation of the statues and artifacts, artwork, original plaster walls, repair of the altar, Sacristy and choir loft. Today it is a fresh bright and most interesting place to visit. For that matter, so is the rest of Mission San Juan Capistrano, but that will be a topic for another day.