© Edgar Mueller / Getty Images

Forget those special glasses with the red and blue lenses—all German artist Edgar Mueller needs to create a 3-D image is a slab of cement and some chalk. Mueller, who began practicing street art when he was 16, is in a whole different league from those who take to the sidewalk with a piece of chalk. Creating his art for festivals around the world, Mueller works with as many as five assistants and for as long as five days to complete his images. Perspective is everything, both for the artists and the viewers; stand in the wrong place, and you’ll see only streaks of paint. But look from the correct vantage point, and the street will suddenly seem to rise and fall with images of glaciers, caves, waterfalls, even the apocalypse. “Close one eye when you look,” counsels Mueller, “And it’s even better.” See more images from National Geographic’s new book,  NatGeo Amazing!, here.