4 articles
Apennine Base Tunnel
The Apennine Base Tunnel (Italian: Grande Galleria dell'Appennino) is an 18.5 km double-track railway tunnel carrying the Bologna–Florence line under the Apennines, opened in 1934.
Baltimore and Potomac Tunnel
The Baltimore and Potomac Tunnel (B&P Tunnel) is a 1.4-mile railroad tunnel under West Baltimore, opened in 1873 and now the oldest tunnel on Amtrak's Northeast Corridor.
Gotthard Base Tunnel
The Gotthard Base Tunnel is a 57 km twin-tube railway tunnel under the Swiss Alps, the world's longest, running from Erstfeld to Bodio and opened in 2016.
Koralm Tunnel
The Koralm Tunnel is a 32.9 km railway tunnel in Austria that opened in December 2025, cutting the Graz to Klagenfurt train journey to 45 minutes.