San Francisco's civic animal might be the crane (Get it? The crane? It's a pun. So funny, you guys.), but our buildings are still old.
In fact, according to this awesome map by the National Trust for Historic Preservation, a huge amount of buildings date from the period between 1906 and 1927, especially in the city's geographic center and north of Market Street.
Out along the avenues, in the Sunset and Richmond districts, the buildings are spring chicken by comparison—with the median of them having been constructed in the 40s and the 50s. By contrast, the section of the city with the newest buildings is the southeast corner. It's also remarkable—though perhaps not surprising—to see a shell of extremely old buildings along the city's waterfront.
The interactive map also lets you visualize the city's employment rate (it's high), density of housing units (not as high as it could be), and increase in property values (highest around the Mission District and Nopa through the Geary corridor). You can also compare San Francisco to Seattle and Washington D.C.
Any big takeaways? We're not so sure. But it's a nifty data visualization and a great way to kill some time at work.