ANSWERS: 3
-
the Seikan Tunnel in Japan, the world's deepest underwater tunnel, is also the longest railroad tunnel at 33.5 mi (53.6 km)
-
In my backyard where the dog tried to dig out under the fence...
-
The Seikan Tunnel is not any longer world deepest tunnel. The deepest tunnel to date is Eiksund tunnel and its depth is 287 m (942 ft) below sea level.
Copyright 2023, Wired Ivy, LLC

by 