Dragon Island

Dragon Island (also known as the Dragons' Nest) is the supposed home of all dragons in the film version of How to Train Your Dragon. It is said that the Vikings have been searching for the Nest since they settled on the island of Berk. After the events of the movie, it was presumed to be uninhabited, and yet it was found to be inhabited by various dragons.

Location
The Nest is located on an island assumed to be far off from Berk. There is a perpetual heavy mist that enshrouds the sea in the surrounding area, preventing anything, save for a dragon, from finding it. The Vikings, under the leadership of Stoick the Vast, were supposedly the first generation of Vikings to be able to find it.

Characteristics
How to Train Your Dragon For three hundred years, dragons lived on the island and made raids on Viking islands such as Berk. On the island in the mountain, the Red Death demanded all the dragons to give it all their food or he would eat them. Hairy Hooligan chief Stoick the Vast and his vikings attempted to find the island before the ice sets, to no avail. The Island was then discovered by Stoick's son Hiccup, and Astrid Hofferson when Hiccup helped and trained the Night Fury Toothless. Stoick then led the tribe using Toothless to find their way through the fog bank. Once there, they attacked the dragons, scaring them away until the Red Death bursted out of the mountain, destroying the ships. However, the Red Death was then defeated by Hiccup and Toothless. Most of the dragons left the island and settled on Berk.

DreamWorks Dragons. When a series of incidents were blamed on the dragons, Stoick ordered Hiccup and his fellow riders to take their dragon to the Island to prevent more incidents. When Alvin and his Outcasts returned to Berk, Alvin took Hiccup to the Island for him to prove that he was the "Dragon Conqueror". It was there that Alvin realized that the Hooligans rode dragons. Alvin and his men were then marooned after being defeated by Stoick, Hiccup and their Dragon riders. It is unclear as to how Alvin and his outcasts returned to their Island.

Lore
The island itself is simple in geography: it comprises jagged rock structures jutting out of the waters, a beach of gravel, and one, sole volcano. Once one bypasses the mist, the chunks of stone scattered about prove to be more than enough of a challenge for most Vikings to navigate through safely, as well as anything else without thorough knowledge of where to go. The beach itself is peculiar in that, rather than being covered in sand, it is composed primarily of what appears to be pebbles. As a result, making contact with the ground on the island of the Dragons' Nest amplifies sound rather than muffling it as would be the case with normal sand, often tipping off the inhabitants of the island to any intruders. When Stoick the Vast stepped onto the island for the first time, all dragon activity seemed to stop immediately. Lastly, the volcano of the island, which, from the base, appears to be nothing more than a mountain, provides the physical structure of the Dragons' Nest. Along the caverns and tunnels that wind around the periphery and inner layers of the volcano presumably live almost all dragons seen in the film. Within the pool of lava in the center, however, lives a Red Death. Though dragons have been long known to gather food from the Vikings or otherwise, it was only recently discovered that this food is delivered to the mouth of the volcano so that the Red Death may feed. Any dragons that bring back a particularly small catch or nothing at all are eaten by it.