Roraima: The Real ‘Lost World’ That Inspired Conan Doyle and Pixar

3,300-foot walls, plants found nowhere else, and a weeklong trek: inside the tepui behind Pixar’s ‘Up’

The Catatumbo Lightning: The Storm That Guided Sailors for Centuries

Up to 297 nights a year of storms over Lake Maracaibo: how it forms and how to see it.

Cascada de Fuego: Why the Water at Salto Golondrina Seems to Catch Fire at Sunset

Every afternoon, for just a few minutes, the water at Salto Golondrina ignites without a single flame. Here’s what’s actually happening.