Glacier Island

Glacier Island appears in Race to the Edge as part of the Barbaric Archipelago. It is the only known habitat of the Snow Wraith.

Description
Led far away from Berk and far out of their comfort zone by clues hidden within the Dragon Eye, Hiccup, Toothless, and their teammates ventured to Glacier Island in search of the elusive, arctic dragon. However, the Dragon Riders were not the first Vikings to venture to this icy and extreme environment. Village elder Gothi was once part of an expedition into these frozen hinterlands years ago in search for pure glacier water, and barely survived the experience. The Snow Wraith is to winter what the Night Fury is to night. It senses the fall of each snowflake. It hears the glacial movement of every iceberg. It feels the slightest change in even the most frigid of temperatures. The Snow Wraith is the sole and uncontested denizen of its island. And when the chill wind roars, it might be the weather, or it might be the Snow Wraith descending upon its next victims.

In Race to the Edge
Many years ago, Gothi and two other Vikings ventured to island seeking glacier water for healing purposes. However, everyone except Gothi were ambushed and killed by the Snow Wraith.

Trivia

 * Glacier Island is very far north as, according to Hiccup's Map, Glacier Island is located nearby Dragon Mountain, which is also located in the far north.