|Location||Wormhole; dimensional world|
Many times, the criminals trapped in there like Gloria, were mass murderers on a grand scale. Some of the prisoners, like General Zod, were stripped of their physical bodies and turned into non-corporeal phantom wraiths.
The Phantom Zone is a desert-like wasteland where the sun never sets. It appears to have no indigenous lifeforms, either animal or plant.
It has what appears to be a river of blood flowing through it and rocky roads, as well as several caverns and caves.
Phantom wraiths roam freely, as do physical entities banished to the Zone.
Powers and Abilities
Time appears to have no meaning in the Phantom Zone. Kryptonians exiled to the Zone don't appear to age or die of natural causes, despite the harsh conditions.
Some entities, like Darkseid, are powerful enough to ambulate and transverse through the Phantom Zone, and retain their abilities.
Strongly resembling wraiths or spirits, the bodiless phantoms roam the Phantom Zone involuntarily, attacking with little to no warning.Though primarily insubstantial and virtually intangible, they are able to cut, rip, and even grab, their victims. (Zod) Only Raya's Crystal of El proved capable of driving them away. Not all prisoners of the Phantom Zone are wraiths, but they are the most dangerous. 
Outside of the Zone, they have not been shown to have any substance; however, they are able to possess a host at will. Once they do so, the host body gains any abilities the phantom may have had in its original form. However, these powers vanish once a phantom leaves, or is forced out, of the individual they are possessing. (Zod, Fallout, Bloodline)
Phantoms can be forcibly removed from a host using a Crystal of El or a similar device, such as the red crystal.
So far, there have been several ways to access the Phantom Zone.
The most common is a procedure through which the person is trapped inside a square crystal shard that has the faces of its victim(s) on it.
From the outside, it seems as if person trapped is somehow stuck within the crystal pane; however, from the inside, these constructs are more like a transparent room from which the person sealed inside can observe the outside world.
Once in space, the 'floor' of this construct drops, and the prisoner inside falls through a tunnel, eventually landing in the true Phantom Zone. Once there, any superpowers that the prisoner may have had are nullified, and the being is rendered mortal.
- Phantom Zone Bracelets
Phantom Zone bracelets originate from Krypton, where Jor-El created the Phantom Zone. They have been shown to be in the possession of the Disciples of Zod.
The bracelets are thrown into mid-air and then turn into a circular portal that then violently sucks their victim(s) inside. Once the victims are trapped, the portal closes and turns into a crystal, the shard then quickly flies into space. (Arrival, Vessel)
Apparently the bracelet was specifically designed to Zod, as it has engraved the symbol of Zod around him.
- The Black Crystal
When Brainiac arrived on Earth, his mission was to release General Zod from the Phantom Zone. He attempted to do this by manipulating Clark Kent into inserting the black crystal into the console of the Fortress of Solitude, opening a portal to the Zone.
- The Crystal of Knowledge
- Phantom Zone Crystals
Both the Crystal of El and the Martian Crystal had the ability to trap in the Phantom Zone. Apparently, the Martian crystal and the first Crystal of El used by Raya and later given to Clark only worked on Zoners that did not have their corporeal form.
Somehow, Clark got a second crystal that did possess the ability to send corporeal beings to the Phantom Zone.
- Through the Fortress of Solitude.
The Fortress of Solitude serves both to open entries to the Phantom Zone and to open exits from it.
On two occasions, Brainiac was able to use the Fortress to generate a portal to the Phantom Zone.
In Brainiac's first attempt, the wraith form of General Zod was almost able to emerge through this, sealed in the crystal square, before Clark prevented it by removing the black crystal that he had inserted in the Fortress' console.
Brainiac's second attempt was successful, and Zod was able to possess the body of Lex Luthor. It is not known if this portal could also have been used to exile someone to the Zone, or if the Fortress itself has such a capability.
- Through the Crystal of Knowledge.
Chloe Sullivan was able to use her Brainiac-given abilities to re-program the Crystal of Knowledge to open an exit from the Phantom Zone for Kara and Clark while the crystal was powered by a frequency generator that Chloe had Oliver Queen steal from Tess Mercer.
The second way to escape the Zone is from the inside. Both gateways are designed by the House of El members.
Both Kara and Clark caused phantoms to escape when they opened the portal on separate occasions. Those transported appear on Earth in a flash of light. When Clark escaped, the exit appeared high in the sky, so he and the other escaped "Zoners" fell to the ground in a burst of energy that created craters wherever they landed.
The Altar has a master crystal key. Without it a member from the House of El can´t open the gateway.
When Clark destroyed the master crystal, it altered the time between the Zone and Earth.
- Jor-El's backdoor.
Jor-El designed a secret 'backdoor' gateway out of the Zone, should he or his family ever be exiled there. When Clark was locked in the prison by Zod, Raya helped him to get out of Phantom Zone and showed him this gateway.
This door is located in the outside in the Phantom Zone and everyone can see it, but can not activate it. To use this exit, the blood of a member of the House of El was needed.
- Zor-El's gateway.
A second gateway designed by Jor-El's brother, Zor-El, was put inside a cave in the Phantom Zone in a secret location and only his family members knew about it.
When Kara was trapped inside the prison, she refused to use the gateway because she didn't want to make the same mistake Clark made when he was in the Phantom Zone and let prisoners out like before. However, when Lois was trapped inside, Kara agreed to open the portal so Lois could return to her world.
- "'Escaped super-criminals from the Phantom Zone' is a little bit of a mouthful." – Chloe Sullivan and Clark Kent, Reunion
Zoners, a term coined by Chloe, pertains to the escaped prisoners and phantoms of the Phantom Zone. When Clark used the House of El gateway portal to escape, it seems that many have followed him back to Earth.
Some Zoners were phantoms, in other words they lacked a physical complexion, allowing them to possess the bodies of humans and apparently, even Kryptonians. They can be sent back to the Zone directly with the Crystal of El, as Clark did with Zod and Baern, without killing the host. Within a corporeal form, they demonstrate their powers.
On the other hand, others were never phantoms and retained their original forms, like Gloria, Aldar and Titan. None of them could be returned to the Zone with the Crystal of El, and had to be killed because there was no Phantom Zone bracelet around to trap them with.
At least four of the escaped Zoners, including Zod, have been shown to bypass or negate Kryptonian physical invulnerability to some extent (and it is imaginable that the Zone holds even more powerful entities). This feat may be related to their imprisonment in the Zone, or that since they are not from Earth and are so physically powerful themselves, they can inflict sharp and blunt force trauma on Kryptonian flesh.
After the Disciples of Zod located Clark and try to force him to release General Zod, Aethyr throws a wrist ring off her arm to form a Phantom Zone vortex to trap Clark in it. However, Clark strongly resists and manages to trap them instead. Then the vortex forms into a giant shard of crystal and flies out of the window and into space.
Months later, when Brainiac tried to complete the mission that the disciples had failed, he was able to open a portal to the Phantom Zone using the Fortress of Solitude. As Zod was appearing out of the Phantom Zone thanks to the portal, Clark with the help of Chloe was able to stop both Zod and Brainiac before anything can happen.
Finally, after an elaborate plan of Milton Fine aka Brainiac, Zod was able to leave the Phantom Zone using Lex as a vessel. When Clark refused to serve Zod, the General tosses a Phantom Zone brasalet out into the sky and it pulls Clark in. Lately, Clark hangs suspended within Zod's former prison, drifting off through space.
Thrown into the Phantom Zone, Clark watched from above as the world became a mess and tried by all means release himself from the crystal prison. However, when the crystal moved away from the planet, Clark falls through a tunnel and eventually land in a desert like zone.
Quickly, Clark finds himself without powers and when began to exploring the area, was fiercely attacked by strange creatures that began to scratching and shaking him. Clark was saved by a woman dressed in strange clothes and was taken to a cave where the woman had her lair.
First reluctant to trust Clark, the woman introduces herself as Jor-El's assistant Raya and explain to Clark that the Phantom Zone was a Kryptonian jail created by Jor-El and that the creatures are revenge-seeking criminals sent there by his father. When Clark tells her that Zod was on Earth, she doubts that Clark can stop him but also explains that there was an exit out of the Phantom Zone, designed by Jor-El in case anyone in his family were imprisoned there.
She helped Clark to locate the gateway and in their way, they were ambushed by the Disciples of Zod, who wanted revenge on Clark. Raya pretends that she is using Clark to escape as only a House of El member can open the portal and after Raya was able to stab Nam-Ek, she gives Clark her crystal and urges him to escape. Clark runs to the portal, placing his bleeding hand on it, pushing him and the other prisoners through.After escaping the Phantom Zone and using the House of El crystal, Clark was able to recapture and re-enclose Zod into the prison. Later, Clark got the goal of back to lock the prisoners who escaped with him.
Clark was able to wielded the Crystal of El against a prisoner named Baern, destroying the crystal in the process but managing to lock him up again.
Later, the Martian Manhunter used his red crystal, a device very similar to the Crystal of El, to remove Dr. Hudson from Clark's mind after he infected him and imprison the wraith in the Phantom Zone once again.
After Brainiac impersonating Kara for several weeks, Clark stopped him and once he exploded, the real Kara was seen trapped in the Phantom Zone´s prison disc spinning through space.
For more than a day of her time there, Kara has been in the Phantom Zone fighting for her life, becoming independent and being a feral warrior ready to pounce on her enemies at any time. She managed to locate her father's gateway out of the Zone, but realized she could not open for she would repeat the mistakes Kal-El made on his last escape here, with company. Months after the Fortress of Solitude collapsed, Lois found the Crystal of Knowledge on the porch of the Kent house and when Clark took it in his hands, found that the crystals had been rescheduled and had opened a vortex to the Phantom Zone. Before he could drive away Lois of all that, the two are sucked into the portal and transported to the intergalactic prison.
After Clark wakes up at the Phantom Zone, he found Lois unconscious on the floor. When Lois wakes, she thinks they have been abducted by aliens and Clark suggests they should stay moving and stick together. After walking for many hours, Lois was getting tired and stumbles onto a dead body and starts to panic. Clark tried to calm her down just as a cloaked figure leaps on them and knocks her out. As Clark was about to fight the creature, he grabs its wrist and was shocked to recognize the silver cuff bracelet of Kara on it and realized that the creature was indeed his missing cousin.
A standoffish and wary Kara explained how she went to the prison thanks to Brainiac and also that she had not escaped because she did not want to make the same mistake that Clark had committed when he was there. Despite being reluctant at first, Clark convinced her to open the portal for Lois and then the three make their way to Zor-El secret gateway. As Clark volunteers to stand guard so that any wraith could pass through the portal, Kara open the portal and pushed Lois into it. However, the Phantom wraith of General Zod´s wife, Faora, was able to outwit the super cousins, and cross the portal, mortally wounding Kara in the process.
Finally, Chloe activated the Crystal of Knowledge opening a portal back to Earth and then Kara and Clark returned to earth safe and sound. Using John Jones´ crystal, Kara was able to extract Faora from Lois's body and send her back to the Phantom Zone.
General Zod was confronted by Darkseid who made a deal with him: He could have dominion over the Phantom Zone and control it after he killed Clark Kent. After the deal, Zod's wraith took over Major Zod's body, gaining all of his memories and he then bared some of Clark's blood. With this new body, he removed the crystal from the El gateway console. There, he had full authority over the Zone and it's inhabitants. As the Zone's leader, he held fight sessions between the prisoners there. Before Clark and Oliver managed to escape, the entrance to the Phantom Zone was destroyed, stranding Zod and the other Phantom Zone prisoners there.
- Phantom Zone
The inside of the Phantom Zone has only been shown three times:
- Phantom Zone portals
Portals to the Phantom Zone have also been seen on several occasions:
- Season Five: Arrival, Solitude, Vessel
- Season Six: Zod
- Season Seven: Arctic
- Season Eight: Bloodline, Beast
In the Comics
In the comics, the Phantom Zone is an inter-dimensional realm outside the normal space/time continuum. It is a barren and insubstantial null area absent of any physical material. There is only one native denizen to the Phantom Zone, the enigmatic and powerful entity known as the Aethyr. All cause and effect that occurs within the zone does so at Aethyr's capricious whim. Persons who travel into this negative zone are no longer corporeal and exist only as psychic phantasms of their true selves. Though their minds and personalities remain intact, they can no longer physically interact with any other being. This includes direct physical contact as well as the power of speech. Communication within the Phantom Zone is done so by telepathy. As the Phantom Zone exists outside of space/time, those within it are no longer subject to the rigors of age, rendering them effectively immortal.
Many years ago, the penal system of the planet Krypton sentenced their criminals by placing them in suspended animation. The Kryptonian scientist Jor-El discovered the existence of the Phantom Zone and introduced it as an alternative means of imprisonment. He had little knowledge of the true inner workings of the zone, but believed that it was a more humane form of punishment over that which they had previously employed. He developed a projection device that could send and retrieve people into the Zone with the simple flick of a switch. The first prisoner to be exiled to the Phantom Zone was the renegade scientist Jax-Ur. Jax-Ur, a former colleague of Jor-El's, was responsible for the destruction of Krypton's moon Wegthor and the deaths of over five-hundred lunar colonists. Over a short expanse of time, the Kryptonian Science Council began exiling the worst of the planet's criminals into the zone, the most famous of which was the military insurrectionist General Zod.
When Jor-El later discovered that Krypton was going to explode due to geological instability, he proposed bringing the entire population of Krypton into the zone. Jor-El never had the opportunity or approval to conduct such a plan, and ultimately everyone living on the planet Krypton died when it exploded.
Those within the Phantom Zone survived, however. It was years before they ever learned the truth about their homeworld's destruction. Several of the exiled criminals, now led by General Zod, found a means of escaping the Zone and eventually came to Earth where they battled the "Last Son" of Krypton, Jor-El's son Kal-El.