It's called the Jacuzzi of Despair, and no living creature has ever escaped from it alive.
Nearly 3,300 feet below the surface of the Gulf of Mexico is a circular pool 100 feet in circumference and 12 feet deep.
The walls that surround it hold in a toxic mix of dense extra-salty brine tinged with methane gas and hydrogen sulfide – curious creatures that happen to wander in don't make it out alive.
Dubbed the Jacuzzi of Despair by the scientists who discovered it, the brine pool "lake" is like an alien world.
"It was one of the most amazing things in the deep sea," says Erik Cordes, associate professor of biology at Temple University who discovered the site and published a paper on it in the journal Oceanography.
"You go down into the bottom of the ocean and you are looking at a lake or a river flowing. It feels like you are not on this world."
The pool was formed when seawater seeped into fissures on the ocean floor and mixed with subsurface salt, and was then forced back up from methane gas bubbling up from beneath.
The water, four or five times saltier than the water around it, is so dense that it stays on the bottom forming the lake; a percolating bowl of toxic chemicals including methane and hydrogen sulfide.
Cordes first found the formations in 2014 with a team of colleagues when they were exploring the area with a remotely operated underwater robot called Hercules. They returned the next year with the small research sub Alvin to get up close, discovering the carcasses of unlucky creatures and cascades where the brine escapes the walls of the lake.
"We were able to see the first opening of a canyon," Cordes says. "We kept up this steep slope and it opened up and we saw all these mud flows. We got closer and we saw the brine falling over this wall like a dam. It was this beautiful pool of red white and black colors."
While rare, brine pools like this have been found before, but not with such a rich ecosystem living on the edges. Here, according to Seeker, mussels with a symbiotic bacteria living in their gills were feeding off the hydrogen sulfide and methane gas surrounding the pool, as well as specially adapted shrimp and tube worms.
The team also collected samples of microbial life that can survive the high salinity and low oxygen levels of the brine pool. Cordes thinks that these creatures could be like life on planets in our solar system or even beyond.
"There's a lot of people looking at these extreme habitats on Earth as models for what we might discover when we go to other planets," Cordes says.
"The technology development in the deep sea is definitely going to be applied to the worlds beyond our own."