Spiral Mountain

The Spiral Mountain is a giant mountain summoned by Bill Cipher as his castle and lair during the events of space. The mountain is divided up into four spirals, each one representing a part of the Planet Popstar under the control of one of the Dark Masters. At the top of the mountain is the utmost portion of Bill Cipher's wasteland, crowned by his castle, which also serves as a meeting place for the Dark Masters. When a Dark Master is defeated, his territory will disappear alongside them. After the Dark Masters were defeated, the "skeleton" of the mountain was destroyed by Supreme King Starscream.

Ocean
The ocean is ruled by The Great Devourer and is protected by Serpentine. Any landmasses that appear here are usually small isles or beaches.

It is where the creature arrive after they were saved by Vitruvius. The beach where Daroach is part of this area. After traveling through the ocean with the help of Ultra Sonic Raider, the children ended up in a small lagoon. Ultra Sonic Raider sacrificed his life to protect the children, and then Dark Daroach was able to kill The Great Devourer with his "Great Tornado". After this the ocean spiral disappeared from the mountain.

Forest
The forest is ruled by Puppet King, and is guarded by Slumbo, Vulk, and Batman; a mansion is hidden deep in the forest, Puppet King resides here when not meeting with the other Dark Masters. The forest floor can be rearranged by Puppet King's remote control; it moves in similar fashion like a treadmill.

He also has small voodoo dolls that control the creature's movements and location throughout the forest; if he moves the voodoo dolls, the victim is teleported to the new location. When Unikitty was playing with Puppet King inside his mansion, he was able to destroy the remote and take the dolls. The forest is mostly made up of locations from the Planet Popstar that had lots of plant life around. Later Infernites Max destroyed Puppet King when he failed to try controling him. After Puppet King met his doom the forest spiral disappeared from the mountain.

City
The city is controlled by General Yakitori. It contained digital analogues of prominent features of cities from the Real World such as Saint Peter's Square, the Arc de Triomphe, and the skyline of New York City, all packed close together into one large city. It even contains hospitals stocked with medicine, which came in handy when Rolly Roll fell ill.

General Yakitori uses his army of Yakitori's Space Mech to track down the creature hiding in the city when Rolly Roll becomes sick. Impatient, General Yakitori then ordered Operation Elimin-8, in which he gave Yakitori's Battle Mechs orders to destroy the city with the children inside. The children survive their attacks, but are attacked by General Yakitori himself. They manage to survive a deadly fall and wind up underneath the city. Under the city is a system of sewers where Yakitori's Giant Mech forced a group of Nixels to supply power to the city above. General Yakitori was eventually killed by Seismo when he sliced General Yakitori into pieces. After this, the city spiral disappeared from the mountain.

Wasteland
The wasteland is ruled by Bill Cipher; he resides in a castle on the top of the mountain. It's both a spiral and the land atop the mountain. However, the land on top the mountain remains even if the spiral vanishes; it was a natural wasteland before. All the land part of the spiral is made from the remaining sections of the Planet Popstar that the other Dark Masters didn't want as a part of their territories; to create despair in those who visit the wasteland, the scenery is consistently black and lifeless.

The caves of this wasteland feed upon the insecurities of those who enter, trapping them in illusions, and only through a realization can someone break free of the illusion. Lazy Island was located in this section of the mountain, desolated and with no chance of new baby Spectrobes hatching; thus true death awaited any Spectrobes that perished.

The final battle with Bill Cipher took place at the mountain's peak, where the creature also faced his bodyguard Dark Daroach and an army of Bill Cipher's Gang. Bill Cipher was destroyed by Mr. Dark's Gate of Destiny.

Trivia

 * With the exception of the view of Earth in the sky, it's impossible to see off the mountain (at the original Planet Popstar).
 * After The Great Devourer and Puppet King perish, the sky around Spiral Mountain grew dark and grim.
 * There is a "skeleton" to the mountain's structure; it only became visible after two territories were removed.