30 November 1990:  It took 25 years to construct Mission Concepción.

"The church walls are 45 inches thick; however only the inside and outside facings
are of solid stone - between the two layers is a filling of small stones and building debris.
The native residents of the missions provided labor for the building of these churches.
This activity was one way to foster a sense of community and provide a means of training
the mission residents as artisans."