Sand dunes in San Francisco


The astonishingly far inland dune-sea at 16th Avenue and Strawberry Hill in San Francisco, approximately 109 years ago, before being engridded and buried by homes.
I remember when an earthquake hit the S.F. area, the instability of highway overpasses and homes was attributed to the vibration-induced "liquefaction" of sand underlying the structures. This old photo shows why that might have happened.

The curves at the top of the picture appear to be part of a frame or an artist's borders on a postcard. Credit, via BLDGBLOG.