The Shadow Track Entrance
The Shadow Track was an old racing track, now abandoned, and was were racers and their dragons who once visited it were never to be found again. It only appears under specific circumstances, and traps humans who enter it with fear. To come out of the Shadow Track safely one must overcome their fears.
It is also known that Armeggaddon was also released from the track when the Dragon Booster freed others trapped inside the track during Episode 17: Faster Than Fear.