A skylight is not just a view to the world above you, but a window to the world beneath. In this photo, taken June 2016 on the Puʻu ʻŌʻō crater at Kīlauea in Hawaii, a volcanic skylight reveals a river of molten rock, drifting just below the charred surface. It’s a powerful reminder of the forces at work below us. Photo by U.S. Geological Survey. Posted on Tumblr by the US Department of the Interior, 7/20/16.