The caverns flooded twice in the past century, in 1937 and 1969. A drought in the mid-1970s opened up previously unexplored sections, down more than 200 feet to level 12, Koppus said.

Cumberland Caverns offers underground adventures with spectacular formations. The Park Theater downtown hosts performances in a beautifully restored 1939 setting. Rock Island State Park nearby ...

Grand Canyon Caverns is about 123 miles from Grand Canyon National Park's South Rim, according to Google Maps. Details: 115 Route 66, Peach Springs. 928-422-3223, gccaverns.com.

Grand Canyon Caverns has reopened after being closed for nearly three years for repairs. Grand Canyon Caverns is in Peach Springs in northwestern Arizona. Two tours of the cavern are offered: 25 ...