About ten years ago, I had a business trip to a bus factory on the south end of San Francisco Bay; we completed our work a day early, so the bus manufacturer gave us a driver who spent the day touring us around San Francisco and the area. The best thing we saw that day was the Marin Headlands: I always sort of wondered what there was on that side of the bay.

Turns out that people of various affiliations have guarded the bay forever, nearly. The most noticeable relics of these defensive are concrete structures that date from World War II.

On my subsequent trips to the area, I kept a close watch on the sky – and in 2009, a clear day made it worth the drive across the bridge for another visit.

Marin Headlands, California
photographed 3.23.2009