There is a history-rich part of London that few people have seen, where the city braced for the Blitz, James Bond’s creator got inspiration and secret Cold War messages passed between Washing ...

Most people exploring a city focus on what’s above ground. But in several cities across the U.S., there's an entirely ...

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

The mystery of an 'underground city' beneath Egypt's pyramids has intensified after scientists revealed a new discovery below ...

The underground cemeteries, nearly 2,000 years old, hold some of the earliest evidence of Christian faith, belief in the ...

Welcome to Falling Waters State Park in Chipley, where Florida’s tallest waterfall plunges 73 dramatic feet into a cylindrical limestone sinkhole, then vanishes completely underground like nature’s ...

A vast, prehistoric city buried beneath the Pyramids of Giza. It’s an extraordinary claim. But a group of Italian researchers claim they have the requisite extraordinary evidence.

The researchers who claimed to have found a vast underground city beneath Egypt's Great Pyramids doubled down on the wild theory Tuesday by saying they've found a second "hidden city." ...

The pipeline from which oil spilled into Baltimore’s harbor is a reminder of the miles of pipes and other infrastructure that lie under the city.