5. Kartchner Caverns – Arizona
This pristine cave in southeastern Arizona only opened to visitors in 1999. Today, tourists flock to see the two-plus miles of passageways filled with rock formations that have been developing for more than 50,000 years.
Self-guided tours are not available, but visitors can choose from several guided tours.
The Rotunda/ Throne Room Tour ($23 adults, $13 ages 7-13, free for under seven) includes a view of both the world’s longest soda straw formation and the Kubla Khan, an impressive 58-foot tall column formation.
Or choose the Big Room Tour (same fees except no children under seven allowed) where you’ll catch a glimpse of the world’s most extensive formation of brushite moonmilk, a creamy white cave deposit.
The Big Room is closed during the summer months when it becomes the roost for the more than 1,000 bats who come to give birth at Kartchner Caverns.
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