The Bay Bridge is the longest steel high-level bridge in the world. The Yerba Buena Tunnel with its diameter of 58 feet, which forms part of the highway between San Francisco and Oakland, is the tallest bore in the world. Additionally, the Bay Bridge can boast of the fact that its construction required the greatest expenditure of funds ever used for a single structure in the history of man. Its foundations extend to the greatest depth below water of any bridge built by man; one pier was sunk at 242 feet below water, and another at 200 feet. The deeper pier is bigger than the largest of the Pyramids and required more concrete than the Empire State Building in New York.

From Symphonies in Steel: Bay Bridge and the Golden Gate by John Bernard McGloin