Pier 70 in San Francisco, California, is a historic pier in San Francisco's Potrero Point neighborhood, home to the Union Iron Works and later to Bethlehem Shipbuilding. It was one of the largest industrial sites in San Francisco during the two World Wars. Today, it is regarded as the best-preserved 19th century industrial complex west of the Mississippi.

Union Iron Works, located in San Francisco, California, on the southeast waterfront, was a central business within the large industrial zone of Potrero Point, for four decades at the end of the nineteenth and beginning of the twentieth centuries.