Connecting the islands of Honshu and Hokkaido, the Seikan Tunnel spans 53.85 km, with 23.3 km under the seabed. Opened in 1988, it’s the longest undersea rail tunnel globally and serves both high-speed and regional trains.
The Channel Tunnel runs 50.45 km beneath the English Channel. Opened in 1994, it links Folkestone in the UK with Coquelles in France, facilitating passenger and cargo rail traffic through one of Europe’s busiest transport corridors.
4. Yulhyeon Tunnel, South Korea – 50.3 km
Opened in 2016, Yulhyeon Tunnel is a 50.3 km double-track railway tunnel on the Seoul Metropolitan Subway. It is one of Asia’s longest urban underground railway tunnels, handling high commuter traffic.
5. Swiss Lötschberg Base Tunnel – 34.6 km
This tunnel in the Swiss Alps has a length of 34.6 km, serving the Lötschberg railway line since 2007. It is an important freight and passenger route enhancing transalpine transport.
6. New Guanjiao Tunnel, China – 32.7 km
Located on the Qinghai Tibet Railway, it measures 32.7 km. Opened in 2014, it passes through mountain passes at high altitudes and helps connect Tibet to the Chinese railway network.
7. Songshan Lake Tunnel, China – 38.82 km
One of China’s longest national railway tunnels, Songshan Lake Tunnel lies on the Guangzhou-Shenzhen railway and stretches 38.82 km. It started service in 2017, with six underground stations along its length.
8. Pajares Base Tunnel, Spain – 24.67 km
Pajares Base Tunnel links Asturias and León regions, facilitating high-speed rail traffic. Opened in 2023, it has improved connectivity in northern Spain.
9. Guadarrama Tunnel, Spain – 28.4 km
Part of Spain’s high-speed rail network since 2007, the Guadarrama Tunnel stretches 28.4 km beneath mountain ranges, supporting fast train services in the Madrid metropolitan area.
10. Taihang Tunnel, China – 27.8 km
Used since 2007 on the Shijiazhuang–Taiyuan high speed railway, Taihang Tunnel is 27.8 km and is one of the longest in Chinese high-speed rail, reducing travel time across difficult terrain.
