DO NOT TOUCH the formations! The Cavern of Sonora is 90% active, alive and growing. Please do not touch anything. Do not bring food, drinks, or anything organic into the cave. Even a copper penny can harm the formations that took hundreds or thousands of years to form. Just look at this lovely formation resembling the wise teacher's hand portraying a 'do not touch' message across the walls of the cavern.
And, for those kids who are totally out of control, the cavern has created the 'Machete,' which will be used to cut the hands and legs of those guilty of destroying this natural treasure. Ok, a bit graphic, but it does put an emphasis on presserving the cavern.
As if the hands of the teacher wasn't enough, the cavern has a 'Watch Dog' awaiting those bad kids that destroy its domain. Ironic, I know, since the watchdog was partly made out of a neglect in the contruction of the tour's path.
There is a section of one tour called "Windy Tunnel". The reason it's called that is because of all the gasping and puffing tour groups are doing after climbing a fairly demanding set of stairs. If you have any issues that might limit your mobility, it's best to ask about the physical demands required of each tour!