Koralm Tunnel
| Koralm Tunnel | |
|---|---|
east side with railjet in 2025 | |
Interactive map of Koralm Tunnel | |
| Overview | |
| Line | Koralmbahn |
| Location | Styria/Carinthia (Austria) |
| Coordinates | 46°45′12″N 15°1′52″E / 46.75333°N 15.03111°E |
| Status | Active |
| Start | Frauental |
| End | Sankt Andrä |
| Operation | |
| Work begun | 2008 |
| Opened | 12 December 2025 |
| Traffic | railway |
| Technical | |
| Length | 32.9 km |
| No. of tracks | 2 single-track tunnels |
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.