Across two very different continents, scientists are mapping vast systems of ancient tunnels that were not carved by rivers ...

Scientists are puzzled by ancient microbial activity found in rock formations in Africa and Arabia, hinting at a different environmental past.

In some of the driest parts of southern Africa, rock faces hold quiet records of much older worlds. Marble and limestone ...

Road construction in Limoges uncovered a ventilation shaft and underground tunnels built by the ancient Romans as an aqueduct. Photo from F. Devevey and Inrap During construction work in a city of ...