The city of Cincinnati never finished building its subway in the 1920s, a decision that has long been second-guessed. The subway tunnel not only sits empty but costs city taxpayers money to maintain.

Cincinnati city leaders are exploring the possibility of transforming America's largest abandoned subway system, located beneath Central Parkway in downtown, into a unique public amenity.The subway ...

The underground tunnel system of Hukok in Lower Galilee provided escape for Jews revolting against Roman rule. A team of volunteers also recently discovered a stash of 22 deliberately hidden—and ...