At the height of the Gold Rush in 1850, thousands of people were sailing to the Bay Area every month. While many were searching for gold, many stayed in town to make money as a merchant, tradesman, and a variety of other jobs.
Bay Area archeologist Dr. Allen Pastron says that once people got here, many abandoned their ships just offshore. Then, when all these newcomers caused a housing crunch, builders looked to the ships for a crafty solution. They would buy those ships for very cheap, haul it up to the pier, tear the mass down, reconvert it a little bit, and end up with an instant building.
When a series of fires swept through the city, they burned the top half of these newly converted ships. The city continued to build upon itself, though, leaving the bottom halves buried underground.
However, that’s not the only way ships got down there. Later, when the city was expanding and filling in the bay, some developers purposefully sank abandoned ships to mark property lines. In fact, there’s still a number of those closer to the Embarcadero.
Dr. Allen Pastron estimates at one point there were more than 50 ships buried under San Francisco, but isn’t sure how many there still are. As the city continues to grow, we may discover even more.