Channel Tunnel Length: 50.5 kms Country: UK and France Transport: Rail

Photographs: Holger Weinandt/Wikimedia Commons

Chesapeake Bay Bridge Tunnel Length: 23 miles (about 37 kms) Country: US Transport: Road

Photographs: Jim Powers/Wikimedia Commons

Tokyo Bay Aqua-Line Length: 9.6 km Country: Japan Transport: Road

Photographs: Courtesy, Yokogawa Bridge Corp

Busan-Geoje Fixed Link Length: 8.2 kms Country: South Korea Transport: Road

Photographs: Asfreeas/Wikimedia Commons

Bomlafjord Tunnel Length: 7.8 km Country: Norway Transport: Road

Photographs: Jarvin/Wikimedia Commons

Eiksund Tunnel Length: 7.7 km Country: Norway Transport: Road

Photographs: T. Muller/Wikimedia Commons

North Cape Tunnel Length: 6.8 km Country: Norway Transport: Road

Photographs: Julo/Wikimedia Commons

Transbay Tube Length: 5.8 kms Country: US Transport: Rail

Photographs: Eric Fischer/Wikimedia Commons

Severn Tunnel Length: 3.62 kms Country: UK Transport: Railway

Photographs: Brett Palfrey/Wikimedia Commons