San Diego County's stunning, world-class coastline from La Jolla to San Onofre, crumbling into the Pacific Ocean at "Earthquake Bay," site of a nuclear power plant, and playground for millions,was wracked by a 30-meter tsunami 2.5 million years ago as postulated in a new paper on original research on possible local effects of the Eltanin asteroid impact. The San Diego Association of Geologists 2012 field trip guidebook presents this story, volcanoes in Oceanside and Carlsbad, mysteries of Solana Beach, earthquakes, landslides, caves, and other tales of geology, history, and changing terra beneath our feet.