The first mission of the Californias was founded in Loreto. Mission San Javier, slightly newer, is about 20 miles southwest of Loreto and is a lovely site to visit within a small village, tucked into a valley area that is quite remote. It is accessible via a two lane mountain road that is succeptible to washouts during rainy weather.
Originally populated by native peoples, a jesuit brother visited the area in 1699 and because there was a source of water there, it was deemed as a place to start some agricultural cultivation (and of course some churching).
The chapel standing there today was built between 1744 -1759.
Search on the www and there is plenty to read about this site, if you want to know more.