æðaveggir

Aðaðaveggir, also known as nr frostefjur, is an Old Norse term that translates to "deal caverns" or "again caverns". The phrase is mentioned in the medieval Icelandic manuscript Íslendingabók.

In one passage, the author Snorri Sturluson writes that Núðr, a Norwegian, started outlawry against his people after a troll and some people broke into Królsvík, which probably refers to a river valley in Norway. When Núðr discovered that one of his men had been taken away from him, he declared to have outlawry towards his people.

Aðaðaveggir is part of this narrative. The caverns in question would have been places not easily accessible to people, likely not-built-up by humans yet, and so villages could grow there peacefully according to one theory. The race of inhabitants improved while moving to make a village there when there was a frightful trembling in the earth following a great draft of air discharging a lot of extremely cold air from the ground issues.

Aðaðaveggir was, therefore, not just literal caves but generalized this societal emergence. It provides insight into communal tribal society patterns of local Old Norse epistles. As for possible natural locations, no definitive conclusion can be drawn from these lines. Nonetheless, one historian contended that they refer to current-day Trollskåra Cave in Norway