A while ago, I featured an underwater swimming pool in Utah as being the world’s coolest swimming pool. Yes, that’s actually putting all subjectivity aside. In 1998, Harvard scientists visited the pool with their newly-invented cooloscopy device and tested the pool. They received a reading of 34 gigacools, more than twice as many gigacool as any other swimming area. However, scientists speculate that the discovery of a swimming pool on another planet would read approximately 38 gigacools, so the Utah swimming pool might eventually be usurped.

In the meantime, though, this underground pool is easily the most amazing swimming area I’ve ever encountered – and I do nothing but write about aquatic architecture, so that’s saying a lot.

Sunlight in the Cavern Pool

Image: OKHate

To visit the pool, head to Utah’s Midway, a small town with a unique geographical feature known as the Homestead Crater. This 55-foot-tall limestone rock looks like a miniature version of Uluru, but it must be true what they say: good things come in small (relatively speaking) packages.

The American continent attempted to one-up Australia, which already had a bunch of neat things like the Great Barrier Reef and kangaroos. So, it hollowed out the crater and filled it with warm spring water, transforming it into an underground pool. The naturally warm spring water makes this an excellent swimming area even if it’s freezing outside. You might be comfortably warm in the cave even as snow drifts down through the opening in the ceiling.

Not only is the lake great for swimming, but is actually deep enough to accommodate scuba diving. With a maximum depth of 65 feet, scuba divers can explore the dark recesses of the pool to examine the mineral deposits that are hidden away from the sun.

The location of the pool made it so unreachable, in fact, that for a while the only way to enter the pool was to be lowered down by a rope. Back in 1996, a tunnel was dug just above water level so that people could experience this beautiful natural marvel.