Channel Tunnel Exploration
What Is the Longest Underwater Tunnel in Europe?

Discover the longest underwater tunnel in Europe—the Channel Tunnel connecting the UK and France, spanning 37.9 kilometers underwater.

Seikan Tunnel Exploration
What Is the Longest Underwater Tunnel in the World?

Discover the Seikan Tunnel in Japan, the world's longest underwater tunnel connecting Honshu and Hokkaido beneath the Tsugaru Strait.