The Črni Kal Viaduct is the longest and the most noteworthy viaduct in Slovenia. It is situated on the A1 motorway over the Osp Valley close to the town of Gabrovica, around 20 kilometers east of Koper. It is named after the town of Črni Kal. The viaduct is 1,065 meters in length and is mounted on 11 Y-formed sections, the most astounding achieving 87.5 m.
The viaduct was outlined by Janez Koželj and Marjan Pippenbaher, who was additionally its constructor. The development work started in 2001 and the viaduct was opened for movement on 23 September 2004. At the point when practically finished in May 2004, it served as a phase of the Giro d'Italia race.
