For centuries, humans have lived underground. Today, that ancient practice is under dire threat—even as cave life makes more ...

Truth is, we don’t know how the Tree of Life will fall, and we don’t know when. It could happen in five years, in 40 years, ...

From falcon -haunted hangouts to heatstroke-inducing ascents, here are 12 dangerous hikes—cited by AllTrails, Redditors, and ...