Boasting a 7.5-mile-long labyrinth of caverns and underground passages, this subterranean gorge plunges 479 feet into the ground, making it the largest underground canyon in Europe.

To mitigate these risks by collecting overflow from smaller rivers and diverting it to the Edo River, the country spent 13 years building the Metropolitan Area Outer Underground Discharge Channel ...

As reports surface about Elon Musk’s Boring Company planning a tunnel beneath Nashville, here’s a look at his existing ties to Tennessee.