[frau kaleun]

Originally Posted by SteamWake

I'm always amazed at how they can dig two tunnels thousands of feet from opposite directions and end up joining right were they are supposed to.

Not so long ago they couldent even accomplish this task with roads.

http://en.wikipedia.org/wiki/Twenty_Mile_Bend,_Florida

The ancient Greeks managed it on Samos in the 6th century BCE.

http://en.wikipedia.org/wiki/Eupalinian_aqueduct