In 2007, a 300-foot deep sink hole opened up in Guatemala City, leaving this view behind:
Pretty amazing. And you would think it would be a fairly rare occurrence for something this freaking big to just suddenly show up in the middle of the street. Until, of course, the next one opens up a few years later and swallows a three story building. Oh, and this one is about 60 feet across and more than 300 feet deep:
It seems obvious to me that aliens are perfecting their laser drilling from space.
Not quite the same, but two related stories: