Hidden World

The Hidden World is the major and titular location that is featured in How to Train Your Dragon: The Hidden World.

Official Description
"The Hidden World is an old sea-faring legend about a land at the edge of the world, where many sailors have lost their ships — never to be seen again. Those who have returned reported sightings of a great waterfall and dragons guarding the entrance to a hidden world beneath the sea. A land from which all dragons hail."

- Dean DeBlois

"This island still holds too many secrets."

- Dragons: Rise of Berk

Development
"We wanted something that transcended the idea of a cave. Part of that was delving into bioluminescence and was of channeling light into this subterranean space with the use of crystals that could carry light from magma. We wanted it to be an exotic world that still feels like it belongs here on earth. But it's still a place for dragons and not for humans."

- Dean DeBlois

Geography
The Hidden World is located within a massive volcanic caldera that serves as a gateway to an endless maze of chambers and tunnels, which in turn work their way around the world. This subterranean world contains bioluminescent fungi, as well as coral and bright crystals.

The Caldera
"The Caldera is a giant collapsed volcano in the middle of the ocean, which serves as the entrance to the Hidden World. The only way to enter the Caldera is by flying in on a dragon."

- The Art of How to Train Your Dragon: The Hidden World

Mushroom Forest
"After a dragon has entered the Hidden World through the Caldera they get acccess to a network of caves deep in the crust of the earth. After a dragon flies through this network they reach the Mushroom Forest, where the Hidden World's bioluminescence is revealed. The Mushroom Forest mainly gives home to many stalactites and stalagmites that are completely overgrown with various sorts of mushrooms."

- The Art of How to Train Your Dragon: The Hidden World

King Island
"At the center point of the Hidden World lies King Island, which serves as the throne room for the king of dragons. The throne for the Alpha is a gigantic crystal on the island, looking over a large part of the Hidden World."

- The Art of How to Train Your Dragon: The Hidden World

Hidden World Annex


"In the darkest depths lies the unknown and it is up to Vikings to explore it! Very few Vikings have been valiant enough to venture into its depths, but those few who have get to witness the light and bioluminescent found within. As dragons seem to take a shine to these underground caves and brightly glow throughout them."

- School of Dragons

Hidden World Caverns
"After the discovery of Hobgobblers, Vikings have been fascinated in learning more of these incredible dragons that has led many to visit their beautiful home. Hobgobblers appear to be small, fierce, powerful dragons but they are rather mischievous in their own way, perfectly resembling the area in which they live; full of mystery and hidden surprises! Vikings can expect these inner caves of the Hidden World to be composed of massive crystal-like structures and have numerous corals running along the open tunnels and like the Annex, a unique touch of gleaming lights can be seen all around. Vikings venturing inside will be left amazed as they watch their dragon light up inside the tunnels. It is indeed as astonishing as it sounds and perhaps that is the reason why these dragons seem to have kept the caverns hidden away from Vikings for quite a while. The caves are full of hidden mazes and tunnels that are sure to test the clever mind of a Viking, and once inside the area reveals beauty unlike anything we've seen before!"

- School of Dragons

How to Train Your Dragon: The Hidden World
Stoick the Vast believed that the Hidden World is a location where all dragons come from and planned to seal it off to stop the fighting between humans and dragons.

Hiccup confided in Astrid about finding the Hidden World so that everyone in their tribe could live in peace. The pair eventually discovered it while searching for Toothless on Stormfly before being chased out by the dragons that reside there, which made Hiccup realize that humans would never be welcomed in the Hidden World.

Following the death of Grimmel the Grisly and the defeat of the Warlords, Hiccup and the rest of the Hooligan Tribe decided to send all of their dragons to the Hidden World, so that no human can ever find and harm them.

About a decade later, Hiccup and Astrid take their two children, Zephyr and Nuffink, to the entrance of the Hidden World, where they find Toothless, the Light Fury, Stormfly, and the Night Light hatchlings.

School of Dragons
The Hidden World appears in School of Dragons in "The Hidden World" expansion. Specifically, a section called the "Hidden World Annex" appears on the School of Dragons Island.

Later, another entrance is revealed on New Berk, containing a Hobgobbler Nest, in the Expansion, "Curse of the Hobgobbler".

SPECIAL SEARCHES WITH TOOTHLESS
The Hidden World first appeared as a special searchable location in December 2018.

LIGHT FURY SEARCHES
In 2019, the Light Fury was released in game as a searching dragon similar to Toothless. She is able to search the Hidden World for specific dragon individuals at certain levels.

Trivia

 * The Hidden World is a famous myth/legend from the distant seas. It is sometimes called "a world beyond the sunset".
 * The Hidden World appears to be an incredibly ancient location due to how massive the stalagmites and stalactites are. This is because rock formations take billions and billions of years to grow just half of the size of the ones that are shown in the film.
 * Dean DeBlois first imagined the Hidden World in a dream as a hole in the sea.
 * Hiccup and Astrid are the only named Vikings to have ventured into and out from the Hidden World.
 * According to Simon Otto, more than 65,000 dragons reside in the Hidden World.
 * According to Brad Lewis, New Berk is supposed to be the mirror image of the Hidden World.