These People Dove 100 Feet Underwater, But They Never Expected To See This

Bikini bottom?

Russian photographer Anatoly Beloshchin has witnessed a lot of exciting adventures in his career — from getting to walk on the icy surface of remote Antarctica to swimming around with massive underwater creatures such as sharks, manatees and even whales.

But when his team set out to visit Mexico, they were hardly prepared to discover something as breathtaking as this.

Beloshchin and his team went scuba diving in one of the cenotes of Yucatán Peninsula. A cenote is a natural sinkhole formed when the ceiling of a cave collapses.

Once the porous limestone bedrock tumbles down, the pit reveals a groundwater pool. The water is said to be crystal clear and the surface — full of subterranean mysteries.

Anyway, back to Beloshchin. The cenote he chose is called Angelita and spirals down almost 200 feet. Beloshchin captured the peculiar underwater world in his photos.

But as he dove deeper, a strange sight began to unfold. It seemed like there's an underwater river submerged at the bottom of the cave.

What does indeed look like flowing river is actually the result of a natural phenomenon called halocline. It appears when waters with different levels of saltiness form into layers because of their variation in density.

In the case of Cenote Angelita, the river is actually just dense saltwater separated from the freshwater by a one-foot layer of hydrogen sulfide.

Pretty neat, huh?