It seen as Hell and the underworld. In the Multi-Universe this is believed to be Hell and where all demonic creatures like him live and Hunson Abadeer rules over it. Funny thing he has never revealed this to any of his followers as his true lair knowing that should anyone get their hands on a follower they will reveal it. Very Few Heroes have been here, due to much not knowing how to get there. Finn, Jake and Marceline have all been there at least once and Lizbeth was there to stop Hunson in The Great Time Travel Adventure
The way to get there
1. Draw a smiling face
2, Douse the face with bug milk
3. Then chant Maloso vobiscum et cum spiritum.