The San Francisco Old Mint, built in 1874 during the gold rush, was once the busiest mint in the United States. One of the last government buildings constructed in the Greek Revival style, it is also the city's oldest stone buildings. The mint operations were moved to a new facility in 1933.
The Old Mint has been closed and abandoned since 1993, threatened by demolition until the federal government transfered the building ownership to the city of San Francisco in 2003.
The current plan is to reopen the Old Mint in a couple of years after extensive renovations, and use it for a city museum combined with shops, restaurants, and office space for nonprofits.
I took those interesting photos in august 2004 during a un-official visit organized by a group of local supporters of the Old Mint.
The highlight of the visit was the underground brick vaults, still equipped with the original engraved safe doors.
Equipment used: Sony DSC F828 (8 Mega-pixel) with 4GB Microdrive.
If you are also interested by urban exploration, i.e. exploring disused buildings and factories, abandoned tunnels, etc, check out www.urban-resources.net, an excellent database of photography books and other resources on this subject.