Col (pronounced [ˈtsɔu̯]; archaic Podvelb,[2] Italian: Zolla,[3] German: Zoll[2][4]) is a settlement on the edge of a karst plateau overlooking the Vipava Valley in the Municipality of Ajdovščina in the traditional Inner Carniola region of Slovenia.

Its location overlooking the valley on the main route leading inland was used in the Middle Ages and later as a checkpoint between the Littoral region and Carniola.

[3][5] Col is located on the border between the historical Habsburg crown lands of Carniola and Gorizia and was a collection point for tolls.

[3] Col was originally known as Podvelb (German: Podgwelb; literally, 'below the arch') in reference to a castle that formerly stood near Saint Leonard's Church.

Archaeological finds at Trilek Castle include a Roman milestone that was found in the 19th century; it bears a dedication to Julian the Apostate and is held by the National Museum of Slovenia.