The Wai-O-Tapu Wonderland in New Zealand is home to a number of roiling, bubbling geothermal sights, but possibly the most intriguing is one of its most calm. Known as the Devil’s Bath, this neon green pool of stagnant stink water is a natural wonder.

Between geysers and colorfully steaming mud bogs, the Wai-O-Tapu volcanic era offers no shortage of wondrous attractions. The Devil’s Bath may not have as many active reactions as other features in the vicinity, but it is still the most eye-catching (and the most intriguingly named). The pool sits in a slight depression likely created from a massive eruption from underground. It is well out of reach of visiting gawkers but can be seen clearly from above. The bright green water gets its color from deposits of sulphur that rise to the surface and float on top. The green identifies that active mineral while other hues found across the park such as blues, reds, and otherwise signify other volcanic elements.

The origin of the demonic monicker is unknown, but given how unnatural the pool looks, it would almost come as no surprise to see Satan himself rise from the still lake. Despite the name and almost frightening display of geothermal chemistry, the Devil’s Bath and all of the volcanic craziness in the area are a favorite attraction for traveling families looking to show their kids how bizarre and unnatural nature can look.