Whereas the Frigidus has been usually considered to be the Vipava River or Hubelj Creek and the battle to take place near Vrhpolje, recent research suggests that it actually took place some kilometers away, between Col and Sanabor.
Dolenje, Ajdovščina, a settlement in the Ajdovščina municipality, Slovenia
In-depth fortifications along the Roman road started at Castra ad fluvium frigidum (today Ajdovščina) and ended at Nauportus (today Vrhnika).
The Godovič Pass is a mountain pass between Ajdovščina and Črni Vrh, both in the Goriška region of Slovenia.
Historically, the upper eastern part of the valley, including the town of Vipava and half of the town of Ajdovščina, used to belong to the Duchy of Carniola (specifically, to Inner Carniola), while the lower western part was incorporated in the County of Gorizia and Gradisca and thus to the Austrian Littoral.