The Northern Markets first appear in the episode, "Saving Shattermaster".
- "Once an unspoiled island, the Northern Markets now house an unsavory port teeming with pirates, weapon mongers, and dragon trappers."
- ―Hiccup's map
This island appears to have a bustling market of sketchy Viking traders and weapon-smiths. The land outside the markets, however, appear to have healthy grass, trees, and other vegetation, on a hilly and mountainous island. There is at least one area along the shoreline suitable for docking ships.
The episode, "Saving Shattermaster", opens with the Defenders of the Wing attempting to buy weapons at the Northern Markets. There is a shadowy figure lurking there that appears to be working with the Dragon Hunters. Upon investigation, the Dragon Riders discover Dagur the Deranged is at the Northern Markets, posing as a friend of the Hunters. His real goal, however, is to save Shattermaster from slavery.
In the episode, "Sins of the Past", a bit more of the market is seen, as Snotlout Jorgenson walks through it in search of chicken feed. He meets a Chicken Feed Salesman. There is also a seedy tavern on the island, where Heather meets Harek to find out information about her father.
The Northern Markets is not seen, but mentioned once in the September 2017 Gauntlet Event. Apparently, according to Fishlegs the Twins visit the Market and purchase a Skrill egg, in order to start a singing band.