The hook
After floods kept drowning it, Sacramento jacked its whole downtown up a full story in the 1860s, and you can still tour the streets and storefronts it buried.
01Why it's worth it
Sacramento kept flooding in the 1850s, badly enough to kill people and wipe out businesses, so the city did something drastic: it raised itself. Over the 1860s and '70s, workers filled the streets with dirt and jacked the buildings up ten to fifteen feet, sometimes with people still living and working inside them, until the old ground floors became basements and the sidewalks were sealed underneath. That buried layer is still down there, and the Sacramento History Museum runs a tour into it, through hollow sidewalks, entombed storefronts, and the sloped alleys the raising left behind. It's the same trick Seattle is famous for, except almost nobody outside the region knows Sacramento did it too. The gold-rush waterfront of Old Sacramento sits on top, worth a wander before or after.
02How to experience it
Tours leave from the Sacramento History Museum at 101 I Street in Old Sacramento, about an hour and three-quarters from the Bay. The walk runs about an hour and tickets sell out in peak season, so book ahead. Combine it with Old Sacramento and the California State Railroad Museum a block away to make a full day of it.