Collossal Cave Mountain Park is a fun little day trip just outside of Tucson that will only take a few hours out of your day. Collossal Caves are a series of caves tucked into the mountains and your ticket which runs about $ 15 includes a one hour guided tour by a very knowledgeable guide. The smell of bat guano will open your nostrils at first but you get used to it after a while. The tour goes through a series of chambers around the caves and the guides take different routes so you see different things each time. There are about 300 stairs up and down total so make sure you have good shoes but I wouldn’t necessarily say it is challenging on the lungs. They let you take pictures along the way, just don’t touch the rocks! There are also intermediate and advance exploration programs available which have you climbing up and around the caverns. While you wait or when you finish, they have an extensive gift shop and small area to order food. There are also some great views! I would not recommend Collossal Caves for children under 5 as they don’t seem too interested in listening to the guides and some of the steps can be slippery and the drop offs along the routes are steep(adult-height handrails are installed).