The Črni Kal Viaduct (Slovene: Viadukt Črni Kal)[1] is the longest and the highest viaduct in Slovenia.

It is located on the A1 motorway above the Osp Valley near the village of Gabrovica, about 20 kilometres (12 mi) east of Koper.

The viaduct was designed by Janez Koželj and Marjan Pipenbaher, who was also its constructor.

[1] The construction work began in 2001 and the viaduct was opened for traffic on 23 September 2004.

[2] When almost completed in May 2004, it served as a stage of the Giro d'Italia race.