If you were to splash New York with some kind of luminescent ink that reveals the age of buildings, this is roughly what it would look like: vast green swaths of 20th-century development, freckled with verdant blue and purple structures slapped together in the 1800s:
This incredible view of one of America's oldest burgs – available for your time-wasting pleasure here – was conjured over two days by Brandon Liu, a 24-year-old computer programmer in San Francisco. Inspired by similar visualizations for Brooklyn and Portland, Liu took a bulging wad of newly accessible open data and used it to create an extremely detailed, color-coded cartography of 1,053,713 buildings. Mauve dates to the 1830s, medium blue the turn of the century, and yellow the mid-1990s. It's zoomable, so you can ratchet down to specific neighborhoods to root out some real geezers hiding among all the fresh-faced facades.