|“Here we try to foster what I call 'an environment of encouragement.'”|
|— Warden Noble|
Kryptarium Prison is a large facility that houses many convicted criminals. Located in the Sea of Sand and operated by Warden Noble, Kryptarium contains some of Ninjago's most dangerous culprits, such as Soto, Pythor, a Giant Stone Warrior, several Skulkin, The Sons of Garmadon and Garmadon himself, and in an erased timeline, the Ninja.
During the Second Serpentine War, the Ninja went to Kryptarium to find Pythor, who was the sole means of allowing Chen's army to be Anacondrai forever. While there, a fight broke out when Kapau and Chope raided Kryptarium. The Ninja battled Chen's Cultists as well as many inmates, before Pythor was ultimately captured. Some time later, the Ninja were framed for a series of crimes they didn't commit and were imprisoned in Kryptarium. They then allied with Captain Soto, who helped them escape. After Jay made his final wish, Soto was put back in Kryptarium and the Ninja were never imprisoned there to begin with.
After the Sons of Garmadon resurrected Lord Garmadon, they were arrested and put in Kryptarium. However, after Garmadon freed Harumi, she freed her allies and took over the prison. That night, Garmadon fought and defeated Lloyd in a brutal battle that took place in Kryptarium.
After Garmadon's takeover of Ninjago, the Sons of Garmadon used Kryptarium as a place to send anyone who opposed Emperor Garmadon. So far the those caught are: Ronin, Police Commissioner, Simon, Tommy, Noble, Karlof, Neuro, Tox, Griffin Turner, Paleman, P.I.X.A.L., Misako, and Bolobo. Those who haven't been caught yet are: Lloyd, Nya, Skylor, Dareth, Mistaké, and the Postman. They later broke out upon hearing the Ninja's return and took it back, sending the Sons of Garmadon and Garmadon himself back to Kryptarium.
- Kruncha (formerly)
- Nuckal (formerly)
- Frakjaw (formerly)
- Giant Stone Warrior
- Nindroid Warriors
- No-Eyed Pete
- Captain Soto
- Pythor (formerly)
- The Mechanic
- Kai (in an erased timeline)
- Cole (in an erased timeline)
- Jay (in an erased timeline)
- Nya (in an erased timeline)
- Zane (in an erased timeline)
- Lloyd (in an erased timeline)
- Hageman Brothers (formerly)
- Monkey Wretch
- Several other Sky Pirates
- Mr. E (formerly)
- Ultra Violet
- Chopper Maroon
- Luke Cunningham
- Lord Garmadon
- Over 300 members of the Sons of Garmadon
Prisoners of Ultra Hunt
- Griffin Turner
- Police Commissioner
At some point in time, prior to the defeat of the Overlord, Kryptarium Prison was built to house Ninjago's most dangerous criminals, and at the same time, rehabilitate them as well.
In an attempt to figure out a weakness of the fake Anacondrai, the ninja visited Kryptarium in order to interrogate a shrunken Pythor. However, the prison was infiltrated thanks to the efforts of Kapau'rai and Chop'rai, and several of the inmates escaped thanks to No-Eyed Pete using a fallen staff to open all of the door cells. However, with the help of the Ninja, the inmates were all detained, save for Pythor, and the prison was eventually repaired.
Shadow of Ronin (Non-Canon)
Shortly after Ronin stole the Ninja's memories, he sent his goons to Kryptarium to get the map to the Inky Lemonberry from Hibiki. However, the Ninja soon arrived seeking Hibiki's help as well and sent the goons in retreat.
After being captured by Ronin, the ninja were sent to Kryptarium, and due to their powerful status, were detained in the section for the most dangerous criminals. There, they were confronted by several angry inmates, including the Mechanic. However, the prisoners were quickly placed into their cells, and at lunch, the ninja managed to learn from Soto the weakness of a Djinn; the Tiger Widow venom. Following a brief skirmish with the inmates, the Ninja agreed to help Soto escape the prison in return for the location of Tiger Widow Island.
As a result of Jay's final wish erasing the events of the season, Kryptarium regained its escaped convict, Soto. Sometime afterwards, Frakjaw later escaped his imprisonment.
Harumi and a resurrected Garmadon broke into Kryptarium and took it over, freeing the Sons of Garmadon. Garmadon used the basketball field to practice on a few members. Harumi later had the cameras broadcast the fight between Lloyd and his father to Ninjago.
Two members of the Sons of Garmadon guarded the prison after several members of The Resistance were captured.
When Chopper Maroon informed the guards they need all hands on deck because the original Ninja and Wu were back, Karlof managed to break Ronin, Griffin and himself out to help break the other prisoners of Ultra Hunt out. After taking the prison back and Garmadon lost his power, the Sons of Garmadon were sent back alongside Garmadon.
- Original concept art depicted Kryptarium as being constructed around a large spire.
- Kryptarium's design is based on a panopticon prison.
- It is unknown what happened to the prisoners when Harumi and Lord Garmadon took over in "True Potential." They were either transferred to a different prison due to the many members of the Sons of Garmadon, were killed by the Sons of Garmadon, or they were freed by them.