The stalactites and stalagmites of Sequoia National Park’s Crystal Cave, a sprawling subterranean wonder that’s been closed for four years, will be accessible again this summer. But to get in ...

fascinating glimpse into the cave's geology, history, and ecology." Good to know before you purchase your ticket? The trail to Crystal Cave is about a half mile long and is described as "steep and ...

NGC goes inside one of the greatest natural marvels on the planet - a giant crystal cave described as Superman's fortress, with magnificent crystals up to 36 feet long and weighing 55 tons.