Arizona's 25 Must-Visit Attractions

19 Go deep at Kartchner Caverns State Park

The Kartchner Caverns were only discovered in 1974 and remained a secret for decades until the museum was ready for the masses. Strict rules remain today—no cameras, water, food, or touching are allowed in the cave to ensure the habitat's preservation. Spectacular areas like the Throne Room and the Rotunda Cavern inspire awe—the unusual formations have been hewn by an unfathomable amount of time, and the stalactites and stalagmites you'll see are still a work in progress. Kartchner Caverns State Park is ADA-accessible. Both tours are excellent and fill up fast, so book in advance to avoid disappointment.