Koralm Tunnel

The 14th longest tunnel in the world

32.9 km · Length

The Koralm Tunnel (Koralmtunnel) is a railway tunnel in Austria under the Koralpe mountain range. It forms one section of the 130 km (81 mi)-long Koralm Railway which links Graz with Klagenfurt. With a length of 32.9 km (20.4 mi), it is Austria's longest railway tunnel and runs at depths of up to 1,250 m (4, 100 ft) below ground. It comprises a pair of tunnels running in parallel, each capable of carrying a single railway track, which are linked together every 500 metres (1, 600 ft). The Koralm Tunnel was officially opened on December 12, 2025, with regular service starting on the 14th.

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

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