4 of 9Nike Missile Site SF-88, San Francisco, California
Hatch that leads down to the "missile garage". Missiles would be lifted up through this hatch and positioned on the rails going left and right. When seen from above the launch configuration is clear - two missiles to the right and one to the left, with the fourth being launched from the garage.
From: Nike Missile Site SF-88 | Album: USA 2018-12