Northern Swamp

"But I have the path of the Flightmare right on this map. For generations, it's gone through the Northern Swamp on the way to the village. Same route every time. If I could only figure out why, we might be able to stop it."

- Fishlegs Ingerman

The Northern Swamp is a location on Berk, and visited during the TV episode "Fright of Passage".

Geography
Despite being named a swamp, the landscape seen in "Fright of Passage" appears more like a rocky meadow with a cave, trees, bushes, grass, and a babbling brook. This stream harbors algae that glows when the Northern Lights - called "Aurvandil's Fire" - appear every ten years.

Fright of Passage
Hiccup sets out to study the Flightmare dragon, which appears on Berk every 10 years. Astrid comes along, but has vengeance on her mind, to avenge a slight made to her relative, Fearless Finn Hofferson.