Underworld

The Underworld or Nether Realm is known to be the home of the Demons, and also said to be their original place of living before their invasion of the aboveground 5000 years ago. The Underworld is described as the deepest place below Novaterra, with some deep dungeons possibly leading into it, but that is unconfirmed. It is also possible that it is a whole other location between worlds that can only be accessed by Dimensional Magic. These theories are yet to be confirmed though.

Geography
Even if the Underworld is seen as a very dangerous and violent place, it depends on the location. From here you cannot see sunlight, as the sky is completely blocked off by the so called Nether Roof. The only entrances to the Underworld are in fact very dangerous as there are very active volcanoes and also giant rivers of lava and natural disasters are very common in those areas. Most of the Demons inhabit the more peaceful areas of the Underworld, where certain strange plants grow that contain nutrients to feed the Demon populace. The depths have been cultivated by several ancient Demon leaders who have made the area a more safer place to stay. Just like on the aboveground, the Underworld also works similarly with the four cardinal directions and strangely enough have the same distance. There are also some places that seem to mimic places on Novaterra, but are drastically different. It is not wise to explore the Underworld on your own.

Biodiversity
The Underworld contains some of the most dangerous species that are alive. If one wants to prove their strength, not even the Underworld is advised. It is believed that most of the dangerous aboveground beasts share some ancestry with the fauna found in the Underworld. There are massive beasts found in the depths in the Underworld Ocean, which no one, even the Demons are advised to enter. Each of the four exits are guarded by four powerful beasts. To the east there's the Chaos Origin Dragon, to the west there's the Shadow Chimera, to the north there's the Cursed Crimson Tortoise and to the south there's the True Golden Phoenix. They are by all means neutral beings to the Demons, and only aggressive to strangers. There are several much weaker monsters also which inhabit their native biospheres.