Pier 70, San Francisco

You are standing at the threshold of what was once the most vital industrial engine of the American West. Pier 70 is officially recognized as the most intact nineteenth-century industrial complex remaining west of the Mississippi River. This sprawling site served as the beating heart of the Union Iron Works, a shipyard that fundamentally shifted the city from a Gold Rush outpost to a global maritime power. For over a century, the deep-water access here allowed the yard to construct everything from the first steel-hulled ship ever built on the West Coast to advanced naval vessels that saw action in the Spanish-American War and both World Wars.