Bermuda may be best known for its pink beaches, turquoise waters, tropical climate, and dangerously strong rum swizzles, but the British Territory has one more selling point hidden underground.
About two million years ago, most of the planet’s oceans froze in the early stages of the Pleistocene era. With more water frozen in ice, the sea levels dropped, and the above-ground part of Bermuda was a lot larger than it is today. During that period, rainwater slowly seeped into the earth, eventually dissolving and eroding the rock enough to form caves.