Kartchner Caverns State Park, Tucson
These caverns use state of the art technology to preserve this living cave. Because of this, photos are not allowed in the caverns.
I've been inside the caverns 4 times and it never gets old. I make sure and take any out of town visitors there, it is a must see.
Kartchner caverns hosts an incredible variety of stalagmite and stalactite formations often considered to be the best in the world. The caverns were discovered only recently (1974) by two Tucsonans and were kept secret for more than a decade to prevent exploitation and vandalism of the cavey´s ecosystem. Unlike the regiony´s other cave attraction, Colossal Cave, Kartchner is still a "living" cave, meaning that water is still dripping within the caves and the beautiful and unusual formations are still "growing."
The caverns are divided into three enormous "rooms," including the Throne Room, the Rotunda Room, and the Big Room. Tours of the first two rooms are operated year-round, but the Big room will only be open six months of every year (mid-October to mid April), because of the caverny´s population of nearly 2,000 bats. Reservations are required for each tour.