Sinkholes are one of the world’s scariest natural phenomena. Over time, water erodes the soil under the planet’s surface until – in some cases quite suddenly – the land above gives way and collapses into the earth.
Even NASA cannot explain it. It’s best to gaze in wonder at the sliding rocks on this dry lake bed in Death Valley National Park. Racetrack Playa is almost completely flat, miles from north to south and miles from east to west, and covered with cr