Far below the surface of Mexico’s Yucatán Peninsula, a flooded labyrinth of limestone tunnels has quietly guarded one of the most haunting fossil troves of the Ice Age. In the darkness of a submerged ...

Mountaineers, cavers, and scientists ventured into the inhospitable caves at the giant volcano’s peak to learn more about how this frozen environment is changing over time. Tabby Cavendish, a ranger ...