Imagine a wave so massive—taller than a 15-story building—that it could rip a boulder the weight of 200 elephants off a cliff and hurl it the length of two football fields inland. That’s exactly what happened in Tonga 7,000 years ago, according to new research. Scientists found this monster boulder, the largest ever discovered on a cliff, and pieced together the jaw-dropping story of the ancient tsunami that put it there.

Editor’s Note: This isn’t just a wild geological anecdote—it’s a stark reminder of how powerful (and terrifying) nature can be. While tsunamis today are devastating, this discovery shows they’ve been capable of mind-bending destruction for millennia. For Tonga and other Pacific nations, it underscores the importance of preparing for the worst, even if the "worst" sounds like something out of a disaster movie. Plus, it’s a humbling glimpse into Earth’s violent past—proof that the planet has always had tricks up its sleeve.