Tunnel
This is an old revision of this page, as edited by DavidB4-bot (talk | contribs) at 01:37, June 28, 2016. It may differ significantly from current revision.
A tunnel is a passageway through or under an obstruction, like a mountain. The world's longest tunnel is 57 kilometers (around 35 miles) through the Swiss Alps, completed after 6 decades of work in 2010,[1] although it is not open to traffic yet. The longest tunnel in operation is Japan's Seikan Tunnel.