I came across this rubble on a stroll through the Presidio. The book I was using for the walk mentioned that it is, most likely, from the 1906 Earthquake. The debris appears, to me, to be stone from burial crypts, perhaps from one of the many cemeteries that were moved from The City to Colma. Either way, they speak to the futility of grasping for permanence in this very impermanent sphere. Think of the money and effort that went into constructing whatever edifice these remains once constituted. Here they lie, forgotten for a century, once someone's"final" resting place, destined someday to be a bench or, perhaps, a retaining wall.