Peppersauce Cave, Natural limestone cave in Santa Catalina Mountains, Arizona.

Peppersauce Cave is a natural limestone cavern in the Santa Catalina Mountains with over one mile of surveyed passages and multiple exploration routes. The system features an underground lake and passages of varying difficulty that allow visitors to choose their level of adventure.

Peppersauce Cave became known to the public through a February 1948 article in Desert Magazine, and a 1951 National Geographic article showed a scientist breaking off a large stalactite for study. The cave has always been open to the public without guided tours, and since 2001 the Peppersauce Cave Conservation Project, funded by the Arizona Department of Environmental Quality, has worked with volunteers to clean it after E. coli and coliform were found in its lakes.

The Signing Room, a junction of tunnels past the Big Room, has a dirt floor and a low angled ceiling within easy reach, so it is covered in signatures. Visitors keep notebooks and pens there to leave messages, and it serves as a common resting point.

Bring multiple light sources, protective clothing, sturdy footwear, and water because the cave maintains a steady temperature of around 70°F. Passages vary in difficulty and physical demand, so assess your comfort level before choosing your route.

The passage called the Rabbit Hole is a narrow opening where visitors must descend head-first to reach deeper sections of the cave. This unexpected maneuver challenges both courage and agility and often becomes a memorable highlight for adventurers.