Health, Science, Environment

San Francisco is the city of the Summer of Love – a place famous for peace rallies and liberal politics. So, a newcomer to the Bay Area may well feel confused at the number of forts and military bunkers clustered around the Golden Gate.

Until recently, large parcels of land in San Francisco and northward, in the Marin Headlands, belonged to the army — which was charged with protecting what was then the west coast’s most important port.