Devils Hole, Cave and lake system in Nye County, United States

Devils Hole is a water-filled cavity in limestone, fed by a geothermal source that maintains a constant temperature year-round. The surface opening leads to a narrow chasm, with walls that drop steeply into the depths and allow only a small amount of light to enter.

Devils Hole was added to Death Valley National Monument by President Harry Truman in 1952. In 1965, teenager Paul Giancontieri and his brother-in-law David Rose drowned during a dive; a later depth-line drop reached 932 feet without finding bottom. The 1991 USGS dive by Alan Riggs, Paul DeLoach and Sheck Exley confirmed a narrow tube at 315 feet, descending to 436 feet.

The site protects a fish species that visitors can only observe from a distance, as direct contact would endanger the habitat. Researchers regularly monitor water temperature and document animal behavior, which underscores its importance for science.

Access is strictly limited, and visitors must obtain permission in advance, as the area is protected. Opening times and visiting rules change depending on the season, so it is worth inquiring with the responsible authority beforehand.

The area where the fish live measures only a few square meters and sits on a shallow platform just below the water surface. Fluctuations in the groundwater level can alter this habitat by a few centimeters and thus directly influence the survival of the species.