OKC Mayor Patience Latting described the city's underground Metro Concourse network as "the largest pedestrian tunnel system ...

Archeologists Put an End to a Centuries-Old Rumor, Confirm the Existence of Underground Tunnel System Beneath Cusco ...

Under Inca rule, Cusco was developed into a complex urban centre with distinct religious and administrative functions. It is ...

The system was created to allow freight to be moved without disrupting traffic but soon came to be used by local oilmen and ...

The Incan Temple of the Sun in Cusco has long been a visual and cultural jewel of the ancient empire. But there’s even more ...

Underneath a European city lies a network of tunnels shrouded in mystery — to date they remain closed the the public and no ...

Italy's Sforza Castle includes a underground passage that linked the Duke of Milan to his wife’s tomb.

Homeland Security officials are searching for the makers of an underground tunnel crossing from Mexico under the U.S. border ...

Cincinnati asked architects and designers to submit ideas to repurpose the city's abandoned subway tunnel system. The ...