“I bring you together to the Lost City of Ouroboros, before the statue of our very own Great Devourer, to speak of unity.”
Pythor to the Serpentine, "The Snake King"

The Lost City of Ouroboros, also known as the Ancient City of Ouroboros or simply Ouroboros, is a massive Serpentine city that was buried beneath the Sea of Sand after the Serpentine War. The Great Devourer was imprisoned underneath the city, and consequently, finding Ouroboros was a key element of Pythor and the Serpentine's plans for vengeance against the people of Ninjago. The city was originally used as the Serpentine's base before they set off to claim the Fangblades.

After retrieving the four Fangblades, Pythor returned to Ouroboros and began awakening the Great Devourer. However, Wu arrived and confronted Pythor just before the Great Devourer rose from the city and consumed them both. As a result, Ouroboros was heavily damaged, yet this didn't stop the Serpentine from using it as their base again, yet once more it was only temporary. The city was abandoned after the Serpentine journeyed to the Stone Army Tomb.

During the Nindroid Conflict, Pythor brought an army of Nindroids to Ouroboros, which was briefly used as their base of operations. While at the city, the Nindroids constructed and launched a giant rocket into space, en-route to a comet that held the remnants of the Golden Weapons.


The city served as the place where the Serpentine studied the stars.[1] At some point, Ouroboros was buried in a large sandstorm and became the Lost City.

The Snake King

Pythor and Skales searched the desert for the Lost City of Ouroboros, and eventually unearthed it by turning a dial buried deep underground. With the city discovered, Pythor summoned the other Serpentine to the city's Slither Pit arena and challenged the four Generals for their staffs. With some help from Skales, Pythor successfully defeated the Generals and united the tribes, shortly before Lloyd Garmadon—spying on them in a Rattla disguise—accidentally revealed himself.

Taking Lloyd prisoner, Pythor manages to capture Samurai X and the Ninja when they arrive, before pitting them against each other in a Slither Pit. However, Samurai X helped the Ninja escape, defeating a few Serpentine and escaping with the Golden Weapons, although Lloyd remained a prisoner.

Tick Tock

Pythor's true interest in the Lost City of Ouroboros was its role as the apparent prison of the Great Devourer; consequently, he began searching for the four silver Fangblades, the keys to releasing the Devourer.

All of Nothing

During the hunt for the Fangblades, the Serpentine largely abandoned the city of Ouroboros, opting to instead create a network of tunnels and a large underground fortress. When Pythor finally collected the four Fangblades, he immediately proclaimed that the Serpentine must return to Ouroboros to awaken the Great Devourer, but the Serpentine insisted on celebrating their imminent victory. This would prove to be a mistake, as it gave the Ninja time to steal the Fangblades and head for Torchfire Mountain to destroy them. 

The Rise of the Great Devourer

However, Pythor snuck aboard the Destiny's Bounty and stole the Fangblades back, immediately heading for the Lost City of Ouroboros. Despite the Ninja's best efforts, the Anacondrai General returned to the arena and used the Fangblades to reawaken the Devourer, and the city was heavily damaged as the monstrous serpent broke free of its prison beneath the arena.

Wrong Place, Wrong Time

Following the Great Devourer's defeat at the hands of Lord Garmadon, the Serpentine used a desert cave as a temporary base, as Ouroboros was apparently too badly damaged to live in. However, sometime later, the Serpentine repaired it enough to use as a staging ground for their forces. When the Ninja disrupted the preparations, Lord Garmadon used the Mega Weapon to travel back in time and negate their existence. As a result of his meddling, the city of Ouroboros began sinking into the sand—as the Ninja had never been formed, the city had never been found.

The Stone Army

After the destruction of the Mega Weapon, the Serpentine returned to Ouroboros where they resumed hosting Slither Pits in the main arena. While Lasha was fighting Lizaru, Garmadon arrived in a Rattlecopter to gather the Serpentine Generals in order to search for the Island of Darkness. They soon departed in a Rattlecopter over the Endless Ocean, only for Garmadon to be pushed out into the ocean by Skales.

The Day Ninjago Stood Still

With Ouroboros as their primary base again, Skales was crowned Snake King over the Serpentine. After the Serpentine were trapped underground again, Ouroboros became uninhabited.

Codename: Arcturus

The city of Ouroboros appeared to have been Pythor's base of operations prior to his return to New Ninjago City, as he led the Nindroid army to it after retrieving the Overlord's body from the Nindroid MechDragon. The villains subsequently used the city to launch Arcturus and hold Kai captive.

Shadow of Ronin (non-canon)

The Ninja drove through the city on route to Ed & Edna's Scrap N Junk from Kryptarium Prison.


LEGO Ninjago: Masters of Spinjitzu

Season 1: Rise of the Snakes

Season 2: Legacy of the Green Ninja

Season 3: Rebooted

Ninjago: Decoded

Video Games


  • Ouroboros appears to be the only Serpentine city.
  • Ouroboros means "snake or dragon biting its own tail" in the Greek language. This is referenced when the Great Devourer is defeated in a similar manner, as well as in the various spiral and circle designs around the city.
  • The Lost City of Ouroboros is a playable place in Rise of the Snakes.
  • The structure in 9450 Epic Dragon Battle represents Ouroboros.
  • There is a typo of the spelling of the city in the Ninjago game app,[citation needed] where it is spelled "Aura Boris."
  • In the Character Encyclopedia, it is misspelled as "Oroboris."
  • It is unknown how from "Wrong Place, Wrong Time" onward Oruoboros appears to be fully rebuilt, but it can be assumed Garmadon recreated it using his Mega Weapon.




Landmarks, Vehicles, and more


Abandoned Village · Anacondrai Tomb · Ancient Pyramid · Birchwood Forest · Blackwood Forest · Billy Badlands · Boiling Sea · Bottomless pit · Caves of Despair · Chen's Camp · Chen's Island · Chen's Monastery · Chrono Crater (non-canon) · Constrictai Tomb · Corridor of Elders · Crashcourse Canyon · Dark Island · Desert Pyramid · Digger's Deep · Digiverse · Dream World (non-canon) · Dungeons of Shintaro · Echo Canyons · Endless Sea · Fangpyre Tomb · Fire Temple · Floating Ruins · Forest of Tranquility · Frozen Ice Pond · Frozen Wasteland · Geckle Strong-Cave · Glacier Barrens · Glacier Island (non-canon) · Golden Peaks · Haunted Hill · Hiroshi's Labyrinth · Hollow's Bluff · Hypnobrai Tomb · Ice Fortress · Ice labyrinth · Infinity Maze · Ignacia · Jamanakai Village · Jankikai Jungle · Kingdom of Shintaro · Mala Wujira · Mega Monster Amusement Park · Metalonia · Mount of Eternal Shadows · Mountain of a Million Steps · Mountain of Madness · Mountains of Impossible Height · Munce Home-Cave · Ninjago City · Ninjago Harbor · Ninjago · Ninjago (LEGO Universe) (non-canon) · Ninjago Sky · Nom (non-canon) · No Man's Bluff · Oni Land · Ouroboros · Prime Empire (Terra Karana · Terra Technica · Terra Domina · Side-Scrolling Platform · Infinity Maze) · Primeval's Eye · Repo yard · River of Darkness · Rock-Bottom · Samurai X Cave · Sea of Sand · Shadow Bay · Shintaro · Shintaro Mines · Shintaro Palace Gardens · Side-Scrolling Platform · Spinjago (non-canon) · Spirit Coves · Stiix · Stone Army Tomb · Tiger Widow Island · Tomb of the First Spinjitzu Master · Torchfire Mountain · Toxic Bogs · Venomari Tomb · Vermillion Swamps · Vlad Tutu's Dance Class · Wailing Alps · Well of Souls · Wildwood Forest


Battle Arena · Biker Tavern · Borg Store · Borg Tower · Buddy's Pizza · Chan's Theater · Chen's Palace · Concert Hall · Dareth's Apartment · Domu · Dragon's Forge · Ed & Edna's Scrap N Junk · Explorers Club · Four Weapons Blacksmith · Fur Mart · Gamer's Market · Garmadon's Dark Fortress · Grand Sensei Dareth's Mojo Dojo · Hanging Temple · Hidden Workshop · Hiroshi Labyrinth Stronghold · Hono Mizu · Kiddie Arcade · Kryptarium Prison · Laughy's · Lloyd's Treehouse Fortress · Marty Oppenheimer School of Performing Arts · Monastery of Spinjitzu · Ninjago City Aquarium · Ninjago City Bank · Ninjago City Hospital · Ninjago City Police Station · Ninjago City Prison · Ninjago Doomsday Comix · Ninjago Metro · Ninjago Museum of History · Old Electronics Warehouse · Oni Temple · Royal Palace · Shifty's Tables · Shintaro Palace · Skull Keep · The Serpentine's Underground Fortress · Steep Wisdom · Temple of Airjitzu · Temple of Fortitude · Temple of Light · Temple of Madness · Temple of Resurrection · · Underground Library · Vermillion Dome of Doom · Wind Farms Power Station · Wong's Costume · Wu's Academy · Yang Tavern


Battle Wagon · Blade-Copter · Blade Cycle · Blue Dragon · Chain Cycle · Chenosaurus · Chen's Blimp · Chen's Ferry · Cliff Gordon's Yacht · Clouse's Earth Mech · Cole's Earth Mech · Condrai Buggy · Condrai Crusher · D.B. Express · Desert Lightning · Destiny's Bounty (2.0 · Black Bounty · Destiny's Shadow) · Destructoid · Dieselnaut · Earth Driller · ElectroMech · Empire Dragon · Fangpyre Robot · Fangpyre Wrecking Ball · Fire Mech · Fire Stone Mech · Firstbourne Mech · Flying Speeder · Garmatron · Ghost Cycle · Ghost Taker GT · Golden Master's Mech · Golden Mech · Hopper · Hover-Copter · Iron Doom · Jalopy · Jungle Chopper Bike · Jungle Raider · Kai Fighter · Kai's Bike · Katana V11 · Katana 4x4 · Lightning Offroader · Lunar Rover · Mech-enstein · Mech Jet · Misfortune's Keep · Nindroid MechDragon · Ninja Nightcrawler · Nya's Bike · Oni Bike · Proto Sam-X · Prototype X-1 · Racing Bike · Raid Zeppelin · Rattlecopter · R.E.X. · Rock Cycle · Rock Roader · Ronin's Mech (non-canon) · Roto Jet · Salvage M.E.C. · Samurai Mech · Samurai Mech 2.0 · Samurai Mech (Stone Army) · Samurai VXL · Security Mech · Serpentine Bus · Serpentine Train · Snowmobile · Skulkin Mech · Sky Shark · Storm Fighter · Titanium Ninja Tumbler · Tread Assault · Ultra Sonic Raider · Ultra Stealth Raider · Vermillion Invader · Vermillion Racer · Vermillion Ship · Warrior Bike · Wu's Rickshaw · Wu's Ship · Zane's Bike · Zane's Titan Mech

Other Realms

Chima · Cloud Kingdom · Cursed Realm · Departed Realm · Djinjago · Never-Realm · Realm of Madness · Realm of Oni and Dragons · Underworld

The LEGO Ninjago Movie Locations

Ninjago City · Ninjago · Bridge of Fallen Mentors · Canyon of General Unhappiness · Firing Room · Garmadon's Volcano Lair · Jungle of Lost Souls · Koko's Apartment · Lost Generals' Lair · Ninja Mech Garage · Ninjago Beach · Ninjago High School · Ninjago Tower · Temple of Fragile Foundations

The LEGO Ninjago Movie Vehicles

Destiny's Bounty · Fire Mech · Flying Jelly Subs · Garma Mecha Man · Green Ninja Mech Dragon · Ice Tank · Lightning Jet · Ninja Helicopter · Piranha Mechs · Manta Ray Bombers · Quake Mech · Shark Mech · Water Strider

In-Universe Books

Boobytraps and How to Survive Them · Book of Spells · Cliff Gordon's Guide to Wooing Women · Desert of Doom · First Spinjitzu Master's Book · Ninjanuity · Ninjelligence · Serpentine Book · Starfarer · Wu's Lesson Book

In-Universe Video Games

Conic the Ratboy · Counter · Dancy Pants · Fist to Face · Lava Zombies · Lightning Larrikin (non-canon) · Pinball Racer (non-canon) · Prime Empire · Sitar Legend · Turbo Street Brawler


Amulet of Protection · Bell of Divinity · Blade Cup · Celestial Clock · Chest Vortex · Dragon Armor (Blade · Chestplate · Helmet · Shield) · Helmet of Shadows · Jadeblade Statue · Lantern · Map of Dens · Map of Fangs · Map of the Golden Weapons · Medallion · Mirror of Fears · Oni Masks (Deception · Hatred · Vengeance) · Realm Crystal · Scroll of Airjitzu · Teapot of Tyrahn · Underworld Helmet

Portals and Gateways

Blind Man's Eye · Glitch · Manifestation Gate · Rift of Return · Temporal Vortex


BorgPad · Borg Industries · BorgWatch · Cell One · Cliff Gordon's Replica · Creatures Beasts & Beyond · Credits · Cyrus Borg's Statue · Darnagom Enterprises · Dapper Dan · Energy Cubes · Fangpyre skeleton · Fireblock SPF-3000 · Hall of Villainy · Health Boards · Illuma-Swords · Infovision · Kai Action Figures · Kai's Headband · Minidroid Chess · Mystery Dust (non-canon) · Original Prime Empire arcade cabinet · Perfect Match Console · Police Commissioner's Model Boat · Ramne Noodle Cart · Robo-arm · Route 23 · Samurai X suit · Shintaro Wings · Shrinking Pill · Soda guzzler · Thermal Kinetic Inverter · Traveler's Tree · Ultra Hunt · Vast Industries

Metaphysical Concepts

The Balance · Death · Souls

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