From a San Francisco Chronicle online article:

As trivia game experts know, San Francisco has had three U.S. mints. The first mint, on Commercial Street, was replaced in 1874 by a grand structure at Fifth and Mission streets. That building, now called the Old Mint, was itself replaced in 1937 by a new mint on Duboce Avenue, which is still coining money,

The newest museum in San Francisco will open in the city’s oldest mint this week.

The Commercial Street building is built on the site of the first U.S. mint in the West, which opened in 1854 during the California Gold Rush to turn nuggets and gold dust into coins and bullion. Later it was used as a subtreasury, where the government stored millions of dollars in gold and silver bars.

To read more: https://www.sfchronicle.com/bayarea/nativeson/article/SF-s-newest-museum-is-opening-in-the-city-s-14494442.php