The cave (for there is only one) in is located behind an iron door set into the hillside close to the Great Basin National Park
visitor center, and most people come to the park only to see the underground features. These spaeleotherms are not comparable to those that fill the vast chambers of Carlsbad Caverns
in New Mexico, but are still most attractive, on a smaller scale. There is a wide variety of delicate limestone formations including unusual large shell-like structures known as shields.
The Lehman Caves cavern may only be appreciated as part of a ranger-guided tour. This costs (2019) $9 per person for 60 minutes or $11 for 90 minutes - although entry to the national park is free - and begin every hour during summer, or less frequently at other times. The passages are subtly-lit, and the guide carries a torch to illuminate features of special interest. On some of the tours, the ranger will turn all lights off for a short while, allowing people to experience total darkness, maybe for the first time - the effect is rather different to a moonless night, for example, as the blackness is absolute and the accompanying silence is quite intense. The temperature underground is a steady 50°F all year; noticeably cooler than that outside in summer, although at an elevation of nearly 7,000 feet, the park is never particularly hot.