Recently, Bruce E. Simmons was hiking in Garin Regional Park near Union City, CA. When he came across this unusual formation and snapped a picture, later posting it on Facebook. It hasn't been confirmed by experts, yet but my opinion is this is Godzilla's footprint. This makes sense since Godzilla is expected to attack San Fransisco in Legendary Pictures Godzilla 2014 reboot.
Run for the hills! Thanks Bruce.