In Mission Bay sits an island with what looks like a large bowling pin on it. Another sits on the west side of I-5 north of Oceanside. I want to know what these are. Some say these are beacons for planes, but during the 1950s, the government strategically placed missile bunkers throughout the U.S., close to military bases. I have a map of Mission Bay from the government mapping convention and on it this island is marked "Government Island Keep Off." Beacon or bunker?
-- Curious, San Diego
Beacon. They're omnis, radio direction finders for airplanes. They're all over the country. They transmit a tone on a specific frequency in a specific direction. A pilot heading for San Diego can point his plane in the proper direction, hear the tone loud and clear, and know they're nosing off course if the tone starts to fade. The bunkers you're thinking of are probably missile silos, huge underground cylinders that have been taken out of commission and are now being sold to the hip and trendy as subterranean condos.