Caño Cristales River, Colombia
Due to it’s extensive habitat of fauna and flora, this flowing river appears in yellow, green, blue, black and red as you travel along it. The rocks here are around 1.2 billion years old, and those who visit call it the most beautiful river in the world.
Sadly, the mining company that owns the caves could no longer afford to keep the massive pumps going to clear the chamber. I believe the pumps were shut down a few years ago and the cavern is refilled with water. The crystals are growing once again, but no one will ever see it.