Fawley Tunnel

Fawley Tunnel, or Fawley transmission tunnel, is a 3-metre (9.8 ft) diameter, 2-mile (3.2 km) long tunnel under Southampton Water between Fawley Power Station and Chilling near Warsash. It carries the cables of two 400kV circuits of the National Grid.

Google Maps ↗ Wikipedia ↗

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).

Other tunnels in United Kingdom

Delaware Aqueduct United States · 137 km Päijänne Water Tunnel Finland · 120 km Orange–Fish River Tunnel South Africa · 82.8 km Ishikawa Tunnel Japan · 78.5 km Brenner Base Tunnel Austria · 64 km Mont d'Ambin base tunnel France · 57.5 km Gotthard Base Tunnel Switzerland · 57.09 km Hong Kong–Zhuhai–Macau Bridge China · 55 km