These Explorers Found An Incredible Phenomenon In The Mountains

Two explorers climbed a mountain in High Tatras, Slovakia and found something breathtaking. 

They walked across a frozen lake at the top of the mountain that was so clear it looked like there were walking over a sheet of glass.

As the video circulated Reddit, one awesome user explained how this happened.

"If the water is cooled too quickly, it doesn't have enough time to reject any impurities as it crystallizes — those impurities are then held within the crystal lattice and distort the crystal lattice. [...] However, if the water cools and freezes over a longer duration of time, it has time to reject these impurities as it crystallizes," said Redditor GeoGeoGeoGeo.