Skaftafell Ice Cave, Iceland
Ice caves are temporary structures that form at the edge of glaciers when flowing water melts a hole into glaciers. The tightly packed ice has very few air bubbles and absorbs all light except for blue, giving the ice it’s unique color.
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.