Posted on June 20, 2011November 2, 2011 Archaeologists Unearth San Francisco History in the Presidio Archaeologists are working in a valley in San Francisco’s Presidio that’s full of city history — from traces of Spanish-era building foundations to cobblestones from the Great Depression. https://mollysamuel.files.wordpress.com/2011/08/presidioarcheology.wav This aired on KQED News.