For thousands of years, Colossal Cave has served as a retreat for people seeking refuge from the Southern Arizona sun. At different times, it has been a home, a shrine, a hideout, a workplace, and even a playground for adventurers. The cave's temperature, however, remains steady at a comfortable 70°F.

Today, as part of the National Historic Register, the property bustles with activity: people hike and bike the surrounding trails, and tours venture inside the cave to explore. During those tours—which are offered daily—guides share the cave's history, legends, and geology amid beautiful cave formations such as stalactites, stalagmites, and flowstone.