The Hayward Fault is a fault threatening the East Bay with destructive earthquakes. The fault is appx 74 mi long. It runs along the western base of the East Bay hills. It runs through many densely populated areas, including the Richmond, El Cerrito, Berkeley (where it passes right down the center of the UC Berkely stadium), Oakland, San Leandro, Hayward, Union City, Fremont, and San Jose.