Vroengard with Doru Araeba on a map of Alagaësia
Vroengard was an island located off the coast of northern Alagaësia. It was home to Doru Araeba, the city of the Dragon Riders. Among the ruins of Doru Araeba the Rock of Kuthian, the magically sealed entrance to the Vault of Souls, was located.
History
Before the Fall, the island was the home of the Dragon Riders. The city of Doru Araeba, located in the east of Vroengard, was their capital.
It was also the site of the last battle of the fight between Galbatorix and the Forsworn and the Riders where Vrael, the leader of the Dragon Riders, made his last stand in battle against Galbatorix, before his flight to Utgard Mountain. During this battle, a Dragon Rider named Thuviel performed a spell on himself, apparently as a last-ditch attempt to destroy the attackers, in which he converted every atom in his body into pure energy, resulting in a nuclear explosion. The spell killed Thuviel and resulted in a blast that decimated the island but failed to kill Galbatorix and the Forsworn, who shielded themselves. The explosion also resulted in the entire island being contaminated with radiation, which was described as an "invisible poison" by Glaedr. The survivors of the blast showed symptoms of radiation poisoning, such as lesions and hair loss, before their death (except galbatorix and the forsworn, of course).
Wildlife
The island was home to several varieties of unique wildlife. Notable among these were the snalglí, a species of gigantic snail that the dragons enjoyed eating for food. After the blast of energy, caused by a rider splitting the atoms of his body, the poison (a.k.a. magical radiation) in the island corrupted much of the wildlife, causing them to adopt unusual physical and magical characteristics, such as burrow grubs.