The tallest waterfall in the South American country of Ecuador recently disappeared! The 500-foot-fall San Rafael Waterfall used to send thousands of gallons of water gushing over the rocky drop. But in early February, it seemed to dry up. Curiously, the river kept flowing downstream. That’s because a sinkhole opened up just a few feet behind the waterfall, allowing the water to cascade in a different location–one that can’t be seen from the usual viewing points.
Did you know? Sinkholes are created when water flows through certain kinds of rock, dissolving the rock and carrying it away. This creates an underground cavern. When the ceiling gives way, it creates a sinkhole. source
Want to know more? Learn about how scientists study caves to understand their secrets at Science News for Students.