The Dragon Hangar is a large building on Berk that is introduced in the second film of the franchise.
Ever since more and more Dragons started to make Berk their home, the village had trouble with finding room for the new residents of Berk. Hiccup, along with Gobber, came up with an idea. The tunnels that were created by the Screaming Death and its smaller brethren, were still intact underneath Berk, along with the natural caves and tunnel system. Hiccup designed a large stable, where all the trained Dragons that didn't have a rider yet could live. This way, both species had enough room. It's construction started about three years after the war with the Berserkers.("Dragon Eye of the Beholder, Part 1").
The Dragon Hangar is a large building that is attached to a large cliff. In terms of outward appearance, the building resembles a large Viking House, with several decorations in the form of flags, torches and Dragon heads. On top of the Hangar is a landing way for Dragons, which resembles a one used for airplanes. There are several entrances. Three on each side, and a smaller one near the Cliff the building is attached too. One large entrance is in the front of the building, which is the main entrance too. With the help of a large wheel underneath, the storm doors can be closed to prevent Dragons from flying out or coming in. The rear exit resembled a giant birdhouse.The Hangar is build above the Harbor. Each dragon had it's own custom stall and the torches of the cave were filled with dragon spit.
From the inside, the Hangar is build in several caves and tunnels. In it, there are many different stables, making it look like an underground village. Though not seen, the Dragons App mentioned there is a Dragon Wash, a Feeding Station and a special entrance for young Dragons.
On several of the walls, Berk's young artists painted pictures.