Go on a walking tour through Crystal Cave, formations in all shapes and sizes, including "cave bacon" and wispy "soda straws." Each room is named for its distinctive formations, such as the Organ Room, Capitol Dome, Cave Dragon, Marble Room, and at one point on the tour, all the lights are turned out and you're in total darkness. May to October.

The tour takes about 45 min. and you can bring kids under 5, but it's a 1/2 mile hike from the parking lot down to the cave, and no strollers or baby backpacks are allowed. The temperature in the cave is 49 degrees (which feels great on a hot day), so bring a sweater, and wear comfortable shoes.

Buy tickets in advance for Crystal Cave at the Lodgepole or Foothill Visitor Center, at least 1+ hour before the tour starts. (You can't buy tickets at the cave itself.) The road to the cave is long and windy, so allow plenty of time to arrive for your designated tour.