Top 7 Underwater Rail Tunnels of the world

Thames Tunnel, London

The first tunnel under a navigable river, symbolizing pioneering engineering from 1825–1843.

Mersey Railway Tunnel, Liverpool

World's oldest underwater rail tunnel, establishing a critical Mersey crossing since 1886. 

Seikan Tunnel, Japan

World's longest tunnel with an undersea segment, a marvel of modern engineering since 1988. 

Channel Tunnel, England-France

Longest undersea portion railway tunnel, connecting two nations since 1994. 

Eurasia Tunnel, Istanbul

Innovative road tunnel linking Asia and Europe under the Bosphorus Strait since 2016. 

Tokyo Bay Aqua-Line, Japan

Combines bridge and tunnel, slashing travel time across Tokyo Bay since 1997. 

East West Metro Tunnel, Kolkata

India's first underwater metro, a quick passage under the Hooghly River since 2021. 

Hong Kong-Zhuhai-Macau Bridge

55 km-long sea crossing with a significant tunnel section, connecting three regions since 2018.