Jewel Cave is the third longest cave in the world, with over 208 miles of mapped and surveyed passages. This underground wilderness appeals to human curiosity through fragile formations, glimpses of brilliant color, a maze of passages that lure explorers, and scientific wealth that remains a mystery. It is a jewel in the National Park Service. Spring brings common rain or snow and varying temperatures. Summer brings common rain in June, with sunny and dry weather in July and August and temperatures ranging from 70 to 95 degrees Fahrenheit. Fall has mild temperatures and occasional rain or snow showers. Winter commonly brings cold temperatures and occasional snow.

Photo: NPS Photo

Photo: NPS Photo

Photo: NPS Photo/Dan Austin

Photo: NPS Photo/Dan Austin

Photo: NPS Photo/Dan Austin

Custer, South Dakota · USA