- Not to be confused with the episode "Island of Darkness."
The Dark Island (also referred to as the Island of Darkness) is the sister island of Ninjago. Originally part of the main island, it was split during the battle between the Overlord and the First Spinjitzu Master.
- Temple of Light: The place where the Golden Weapons were forged.
- River of Darkness: A long winding river leading to the Temple of Light.
- Jankikai Jungle
- Shadow Bay
- No Man's Bluff
- Digger's Deep
- Lord Garmadon's Camp
- Celestial Clock: The location of the Helmet of Shadows until Lord Garmadon removed it.
When the First Spinjitzu Master battled the Overlord for control of Ninjago, the latter's Stone Army threatened to overwhelm the former. In desperation, the First Spinjitzu Master used his powers to split Ninjago in two, with the Overlord's side becoming known as the Island of Darkness.
Many years later, a group of pirates, led by Captain Soto, sought the Island of Darkness. They set sail across the Endless Sea in their ship, Destiny's Bounty, but the navigation skills of No-Eyed Pete (or lack thereof) caused them to crash before they ever found the island. Later still, Lord Garmadon discovered mention of the island in Captain Soto's journal, and became determined to find it himself.
Lord Garmadon would not actively pursue this goal until after the loss of his Mega Weapon, at which point he informed the Serpentine Generals of the Island of Darkness. Despite Skales' skepticism, the generals accompanied Garmadon as he took a Rattlecopter over the ocean. However, Lord Garmadon was betrayed by Skales and pushed out of the Rattlecopter into the water below.
Ironically, Skales's betrayal led Garmadon to the object of his quest—when he next awoke, he found himself lying on the shores of the Island of Darkness. The Overlord appeared before him and led him through the jungle, until Garmadon came upon a large boulder with four hand dials in its surface. Using his four arms, Garmadon turned the dials, causing the full Island of Darkness to rise from the sea.
At the Island, the Overlord has Garmadon scale up a mountain to show him the Celestial Clock.
Zane sends his Falcon to the Island, only for it to be shot down by a Stone Warrior. Later, the Stone Army are collecting Dark Matter.
The Ninja, having finally arrived on the Island, started to hide their Bounty to ensure the Stone Army can't find them. They later spotted the Temple of Light above one of the mountains.
On the Island, Garmadon laments to the Overlord that he has to battle Lloyd to take over Ninjago. Meanwhile, the Ninja are using their new powers, which Wu tells them to stop because it might reveal their location. Later, when the team failed to put the helmet back on the clock in time, they fell off the cliff and into the Endless Sea.
With the Garmatron ready, the Stone Army head to the coast of the Dark Island to fire the weapon at Ninjago. They left the Island through a portal, leaving the Ninja behind.
The Ninjas' hopes are diminished because the Overlord is at Ninjago City and there is no way off the island. When they followed the Falcon, they found the Golden Mech and the Ultra Dragon came to pick them up.
After the Final Battle
At one point, the Ninja returned to the Dark Island to retrieve the Fire Mech which would eventually be used to scale the Wailing Alps.
Shortly after the Battle of Stiix, Clouse journeyed to the Dark Island, intending to destroy the Temple of Light with the help of the Sky Pirates. Using his magic to influence the Dark Island, Clouse created storms off the coast of the Dark Island which would entrap fishermen long enough for the Sky Pirates to capture them. The fishermen were then taken to Digger's Deep and forced to mine for Dark Matter.
The reports of missing fishermen prompted Misako and Ronin to sail to the Dark Island where they discovered Clouse's plan. They attempted to escape, but Ronin was knocked overboard while Misako was captured by the Sky Pirates. Despite Misako's warnings against doing so, Wu soon led the Ninja to go to their rescue, only for the Destiny's Bounty to be caught in a storm that scattered the group. Wu and Lloyd were soon reunited and began traveling inland aboard the damaged Bounty, while Jay and Nya encountered the Sky Pirates and were reunited with Ronin.
Wu and the Ninja eventually discovered Clouse and his plans for the Dark Island.
- After being separated, the Island of Darkness and the Ninjago mainland appear as the symbol of Yin-Yang, to indicate equal balance between Light and Shadow.
- Just as the Yin-Yang symbol has a contrasting point in each of its halves, the Island of Darkness has a single area of Light (The Temple of Light).
- The Island of Darkness and Ninjago are both shaped like Dragons.