Kalk Trophy | MTB-Bergrennen + Tunnel-Berglauf

The Kalk Trophy Tunnel-Berglauf runs through the Pfaffenboden quarry. Participants navigate the Elfi-Tunnel, Upper Austria's longest tunnel, with a continuous 15 percent gradient for 3.5 kilometers underground. First held in 2009, the course attracts health-conscious amateur athletes. The fastest mountain runners qualify for a special MTB tunnel race.