Kartchner Caverns State Park is near Benson, AZ. We had heard of it from other RVers. The state has made a great effort to keep it as a living cave. As such, it is fairly warm and humid inside the cave. They have installd several walk-in cooler type doors that you go through to enter and exit the cave to preserve the interior atmosphere.
They don't allow any pictures to be taken in the cave so you are out of luck on that count. But there are so many more stalagtite and stalagmite formations than I have seen in other caves because the formations are still being created.