An Insanely Detailed, Hand-Drawn Map of San Francisco

For London's Jenni Sparks, it can take months to make a city map. And that's just the planning process, in which the 25-year-old illustrator roams around checking out corners, snapping photos, watching documentaries, and interviewing locals.

When she is ready to start putting in 10-hour days of drawing, it can still be ages before she finishes—or three months more in the case of this fantastic, crazily detailed map of San Francisco. Her devotion to cramming cartography with every facet of a city's personality, including references only locals would get ("Karl the Fog"?), guarantees that viewers can peruse it for hours and have new stuff to discover the next day.