Researchers have uncovered hidden underground tunnels beneath Milan’s Sforza Castle, revealing a new chapter in the city’s ...

Deep beneath the hillsides and suburbs of Brazil, there are tunnels so vast and regular that they look like abandoned subway ...

A third camp says the tunnels may have existed — anything is possible, really — but any subterranean structure has long since filled in, caved in or been in other ways irreparably damaged and lost to ...

Sinkholes are not unusual in Florida. Tunnels are a different matter. The FBI is investigating the discovery of an underground tunnel that appears to lead to a Chase bank in Pembroke Pines, the ...

Billionaire entrepreneur Elon Musk's mysterious tweets about tunnels have sparked a flurry of speculation about his next project -- and he apparently did some research last week in D.C. The founder of ...

Toronto police said Monday they now know who dug a tunnel near a major sporting venue in the city -- a mystery that has been a source of widespread speculation and conspiracy theories. In a statement, ...

A large dirt pile appears to block more of the tunnel. A tunnel with an unknown origin has been discovered in Alton. Located at 322 Langdon St. in Alton, the tunnel was discovered by accident by ...