The Ghost Zone
All matter and energy of the Ghost Zone is composed entirely of ectoplasm. The Ghost Zone coexists with Earth; they are the proverbial "two sides of the same coin" to each other. Anything that happens to one world also affects the other world in some way.
Doors float through the void of the Ghost Zone, providing access to other realms within the Ghost Zone such as ghosts' homes or lairs. In the very rare event that two or more of these realms collide, black holes can form.
Long ago, when Pariah Dark was first defeated by the ancients, the Ghost Zone fell into anarchy. Though, given what was seen of Pariah Dark, this was for the best. As a result, the Ghost Zone split into sections, each being controlled by a different ghost with a different set of rules. This is why each ghost met in the Ghost Zone has their own island. Skulker has his hunting island, Aragon has his kingdom he froze in time, Walker has his prison, etc. This would explain why not every island follows the same rulebook or logic. 
- Main article: Ghost Portal
There are also many natural portals that open and close without warning and lead to various locations in space and time, such as the Bermuda Triangle, the Denver Dodecahedron, and the Salem witch trials.
Notable Locations in the Ghost Zone
Acropolis of Athens
Home to Pandora and the other Greek and Roman mythological figures. It is the home of Pandora's Box, which Pandora has sworn to keep locked up to prevent the evils within from escaping. It resembles the Acropolis of Athens located in Greece on Earth.
A kingdom governed by Prince Aragon. It is a castle where time does not flow, and is literally stuck in medieval times. During "Beauty Marked", Aragon's sister Dorathea rebelled and made time return to flowing regularly.
Ghostly Black Holes are rare but destructive. They function the same as black holes in space (infinitely deep depressions in spacetime) in that anything and everything near it gets sucked it and not even light can escape.
In the Ghost Zone every realm, section, or kingdom has its own unique ectoplasmic energy surrounding it. Every section has it, and no two are the same. When two sections get too close together, likely when they are nearly on top of each other, the two ectoplasms get too compacted and, due to their density, their gravitational strength increases until light cannot escape, forming a ghostly black hole.
This huge cavern is one giant mouth that eats everything inside it.
The home of Clockwork, first seen in "The Ultimate Enemy". This building is filled with time-related objects such as clocks, gears, and bells, and contains portals that Clockwork uses to view other times and places.
Clockwork and his lair are immune to alternate time paths and time paradoxes. Clockwork's lair is the current location of the Fenton Thermos that contains Dark Danny.
The Elsewhereness is a place where all fear, pain, and misery don't exist. Every ghost wants to be there, but no ghost knows where it is. Even evil ghosts seek this paradise, however Plasmius is the only one who wishes to find it to take control and rule over it.
The only ghost rumored to have found it is Sojourn, who documented the discovery in his journal. Some of the journal pages, which contain clues to the location of the Elsewhereness, are floating randomly throughout the Ghost Zone, though a few have been gathered.
Mentioned in "Fright Night". It is likely the frozen, snowy wasteland where Klemper is seen in "Fanning the Flames". At the end of the episode, Ember is trapped here with Klemper following her, but she later escapes.
The Lightning Arch is the entrance way to a maze leading to Pandora's Castle. Throughout the maze there are several mythological creatures guarding it: Minotaurs, a Centaur, and a Cyclops.
Observants High Council Tribunal Headquarters
From this location, the Observants watch over Earth and enact judgement on ghosts who damage it.
This is the castle of the once great Pariah Dark, who rests here for all eternity. Pariah Dark was accidentally awakened in "Reign Storm" by Vlad Plasimus, but he, Danny, and a wide range of ghosts managed to return him back to his sleep.
Frostbite and his yeti-ghost people live in a freezing cold wasteland. They are a warrior race and skilled with medicines and technology. This is one of the few realms in the Ghost Zone where Danny is actually welcome.
This is a river with a cascade, full of a disgusting, foul-smelling yellow liquid, inhabited by a giant yellow creature with a terrible breath.
A floating jungle-filled island-like land mass, home to rogue ghost hunter Skulker. Danny and Valerie once had to traverse it while handcuffed together as Skulker gave hunt to the both of them in "Life Lessons". It's implied that Ember briefly lives here, as she says in "Girls' Night Out" that Skulker "can't even find the T.V. remote" after one of their fights.
Sidney Poindexter's School
An entirely black-and-white world of the 1950s located in apparently the Ghost Zone's version of Casper High School, holding students modeled after that time period. It was the "home" of Sidney Poindexter. First seen in "Splitting Images". This was the first part of the Ghost Zone seen.
A part of the Ghost Zone where various objects and items from the human world end up, seen in "Prisoners of Love". The Box Ghost said that here was where ghosts end up when released from the Fenton Thermos (though he could have been referring to the Ghost Zone itself).
The Unworld is a limbo-like nightmare realm located between Earth and the Ghost Zone. If exact calculations aren't made when constructing a ghost portal, the portal will lead to the Unworld instead of the Ghost Zone.
People in the Unworld have no human or ghost abilities, and are trapped forever.
The prison where Walker places the ghosts he arrested in jail. Walker once sentenced Danny to 1,000 years in this prison for bringing an object from Earth into the Ghost Zone.
Presumably the Box Ghost's home, filled with boxes which he at times uses as weapons.
Government and law
In the past, the entire zone was under the iron fist of King Pariah Dark, powered by the Ring of Rage and the Crown of Fire. However, his harsh rules caused the ghosts of that time to rebel and place him in the Sarcophagus of Forever Sleep, removing his crown and ring.
In present time, each of the ghosts' lairs seems to operate under its own set of rules, mostly independent of others' influence in a form of anarchy. Walker is an exception in that he interferes in everyone's affairs to enforce his rules and imprisons those who violate them.
There is one law that all ghosts adhere to without question: to never fight during Christmas Day. This is known as the "Christmas Truce," and allows for all ghosts to enjoy 24 hours of peace. Any ghost that violates the truce will be immediately punished by other ghosts if discovered.
- The Ghost Zone is a parody of the Phantom Zone from DC Comics.
- In fact, Butch Hartman personally stated on his Youtube channel that he originally wanted to call it the Phantom Zone. 
- In a way, the Ghost Zone is basically the Spirit Realm or the afterlife, the dimension where people go when they die. It can also be compared to the "Great Fixed Gulf" of Luke 16:26.
Click here to view the gallery.
- 103. "One of a Kind" (mentioned)
- 105. "Splitting Images"
- 108. "Prisoners of Love"
- 111. "Fanning the Flames"
- 113. "Fright Night"
- 114. "13"
- 115. "Public Enemies"
- 116. "Lucky in Love"
- 118. "Life Lessons"
- 119. "The Million Dollar Ghost"
- 204. "Reign Storm"
- 208. "The Ultimate Enemy"
- 210. "The Fright Before Christmas"
- 211. "Secret Weapons"
- 213. "Micro Management"
- 214. "Beauty Marked"
- 302. "Infinite Realms"
- 303. "Girls' Night Out"
- 304. "Torrent of Terror"
- 306. "Urban Jungle"
- 307. "Livin' Large"
- 308. "Boxed Up Fury"
- 309. "Frightmare"
- 310. "Claw of the Wild"
- 312. "Phantom Planet"