The Barrier Mountains are a mountain range found around Magix. It is the border between the known regions and the completely unexplored regions of Magix.
The Barrier Mountains are first mentioned when Stella was turned into a monster by Chimera in Season 3. After escaping from Solaria the Winx girls went to Alfea where Concorda showed them a book in which there was a solution to Stella's problem. According to the book only the Mirror of Truth found in a cave on the farside of the Barrier could give Stella back her real appearance. Concorda then told the Winx that the Barrier was located around Magix and that their journey would be dangerous Mirror of Truth was guarded by icy storms and winged sentries. When the Winx went to look for the Mirror of Truth, they were attacked by giant griffins before they could find the Mirror of Truth.
The Barrier Mountains appeared again when the Winx went to take the Water Stars from the Golden Kingdom. They had to go to the Veil Mist Forest found on the other side on the mountains and look for the Portal of the Golden Kingdom at the bottom of the Red Tower. When the Specialists' ship approached the forest, their navigation instruments stopped working and told them there was nothing there, not even the forest. On reaching the forest, the Winx were attacked by tree-like monsters and by the centaur guards of the Golden Kingdom. In the forest, only the Pixies could feel where the way to the Portal of the Golden Kingdom was and they lead the Winx to it but they had to return to the Pixie Village because it was dangerous for them to go close to the Red Tower.
- Riven was able to go to the Veil Mist Forest alone on his Wind Rider and the Pixies were able to return to Pixie Village without the Specialist aircraft through which they went to Veil Mist Forest. However it is unknown how they were able to cross the Barrier Mountains on their own.