Q&A: Chris Groves – Exploring Underground Water Systems in Mammoth Cave

Renowned cave explorer Dr. Chris Groves goes deep into Mammoth Cave to see how torrential rainfall above affects underground rivers and ancient passages.
Video: Following the Hidden Waters of Southwest China's Karst Region

Video: Following the Hidden Waters of Southwest China’s Karst Region

A look at what is commonly considered the greatest Karst landscape on earth, and its secret waters that flow underneath.

China Karst | Slideshow

China’s Karst Region: Infographics

As they span significant areas of Asia, Europe and the Americas, karst landscapes cover some 15 percent of the Earth’s land mass. Scientists estimate that these areas of porous bedrock are home to as many as 1.5 billion people, a quarter of the global population.