Askja

Askja Volcano is the largest volcano on the main island of Yggdrasil.
Askja was named after the shieldmaiden Askja who defeated the Greatwyrm Yggdrasilix. With the death of Yggdrasilix, the activity in Askja volcano dramatically slowed down to a state which the great sages deemed dormant, but also marked the beginning of Yggdrasil's extended and permanent winter.