The Shadow Isles are an archipelago of islands located northwest of Valoran.
"The Shadow Isles. . . They say they don't exist. Mythical islands haunted by ghosts and spectres. Tales to frighten children. But I know better. I have been there. When I first set foot there I immediately knew something was wrong with that place. My skin crawled and in the pit of my stomach I felt a terrible revulsion. Life didn't belong there. But I also knew... somehow, deep inside I knew that the islands welcomed me. They wanted me.
As I wandered deeper I saw death all around me. Ghostly trees, grass and flowers engulfed me in their horrifying radiance. It was so quiet and so beautiful. I passed my hand through a spectral leaf fluttering in the wind; but there was no wind. That was when I understood that death was another world and I was at its door."Then I heard the song; the spider's song. My companion cried out in terror and fell to his knees. I embraced him. I told him he had nothing to fear. He was going to a better place. I will take them all to a better place."― Elise
Little is known about the mysterious Shadow Isles. An eternally thick, unnatural fog blankets the islands from the view of outsiders. It is thought that the islands are home to countless forms of undead, though no one seems eager to perform the exploration necessary to find out the truth.
Most of the Shadow Isles' history comes from the two mysterious altars of the Twisted Treeline, that says fragments of their history to its capturers and from the League records of the Shadow Isles' champions.
The Devastating Ritual
Before the Shadow Isles became a land of death, the islands teemed with natural life and beauty. This was never truer than in the isles' sacred forest: a paradise of thriving trees and countless species, both animal and spirit alike. When the king of the Shadow Isles ordered his sorcerers to crack open the barrier separating life and death, the forest served as a well of power the magi drank deeply from.
The sorcerers' ritual succeeded in corrupting the cycle of life and unleashing forces they could not hope to contain. Vitality seeped from every living thing in the Shadow Isles: great trees withered into gnarled husks, people warped into twisted shades, and forest spirits became hollow wisps. Maokai, the Twisted Treant , the strongest spirit of the sacred forest, watched in horror as his world crumbled and died around him. He fought to mend the wound in the world, but could not halt the destruction wrought by the human folly. As the ghastly energies sought to overwhelm the great spirit, he made one last desperate attempt to preserve the life of the land. Maokai inhabited the ancient oak at the heart of the forest's spiritual power. There he gathered the essence of the isles into the tree as the corruption of undeath clawed hungrily at anything within reach. Fortified by boundless magic, Maokai could not be consumed entirely, though the spirit was not left unscathed.
Maokai, now saturated with the essences of life and death, became fused with the ancient oak and contorted into an abomination. For ages, pain and grief were the only companions the spirit had. His boughs grew heavy as he wept at the desolation of everything he had known and loved, and his roots tore from the earth as he raged at the reckless sorcerers that had ruined his home. But all was not lost. Maokai had preserved the last vital spark remaining in the Shadow Isles, and with it, the hope of returning life to the land.
Like moths to a flame, the tormented shades of the Shadow Isles were drawn to the living essence within Maokai. The spirit guarded the seed of life from the relentless undead, but Maokai knew he could not fend them off forever. He needed to escape the land of death his home had become, so he cast himself into the sea and trusted in nature to guide him towards a living land. There he hoped to find the means to cast out the forces of undeath and restore life to the Shadow Isles.
Denizens of The Shadow Isles
Mordekaiser, the Master of Metal seem to hold a high position on the island, but none is quite sure. The dreaded Hecarim marches through Valoran for the Shadow Isles. Thresh, the Chain Warden is yet another creature with ties to the Isles. Legends speak of a prison warden with a fondness for torture, whose preferred tools were chains. It's not surprising that such a monster's spirit would come back, armed with the chains. His sole purpose is finding worthy souls, breaking the minds and bodies of their hosts, and then carrying them back to the Shadow Isles, where an unknown (but most likely terrible) fate awaits them.
Evelynn, the Widowmaker, is also a creature believed to have originated from the Shadow Isles as well. It is clear upon first meeting her, and surviving, that she is not quite human. Some theorize that she was cursed with a mild form of fantastical vampirism as a child. Supporters of this theory contend that her ability to sap the very life essence of her opponents while still being able to tolerate direct sunlight, would account for this belief. Another popular theory is that she abused the use of magic as a child, morphing her into the hungering beast her opponents see on the battlefield.
Immigration to the Islands
Some deviant few willingly make the dreaded islands their home. His perverse obsession with death naturally led Karthus, the Deathsinger to willingly join the unliving. Others, naturally, move for work. there are many shades of death, and each is embrace. To rise from one state to another requires the magical aid of a skilled professional. Yorick, the Gravedigger washed ashore and now act as a ferryman for the Isles' undead denizens, helping them climb death's many-tiered ladder. Elise, the Spider Queen, travel there for religious reasons. She worships the Spider God, Vilemaw  Every year she return to the Isles with a select few disciples. Then she feed them to their god in exchange for a youth-prolonging gift of venom. She would again return to Valoran preaching her deity and leading a pilgrimage again by the end of the year.
- On the Shadow Isles, there is a saying, "Death is but a new beginning."
"As the fog parted and I first beheld the Shadow Isles, I sensed immediately that something was amiss. From the mysteriously placid waters of the bay to the dead calm of the night air, an eerie stillness gripped the place – even the sea and sky. Even as I made ready to go ashore, the crew begged me to return at once to the mainland."
"Despite its size, the immense forest loomed like a sepulcher around us, and the dank air and unnatural stillness bred increasing feelings of paranoia and dread. My companion begged me to turn back, but some primal yearning spurred me onward, deeper into the gloom."
- The quote of the western altar, "This place was once... so beautiful.", suggests that the Shadow Isles, and all its inhabitants, were transformed by the Rune Wars or by some other catastrophic event. The latter is confirmed by Maokai's lore.
- The altars on the Twisted Treeline suggest :
- The quote of the western altar; "I serve you, because I must, Mordekaiser."; and the eastern altar "I serve you gladly, Mordekaiser.", Mordekaiser holds some rank in the Shadow Isles, further evidenced by his old lore which stated that he was an undead general.
- The quote of the Western altar; "Mordekaiser is not to be trusted Hecarim!", taking in count that Hecarim fights for the Shadow Isles, Mordekaiser actual goals aren't linked to the Isles, but to his personal benefits.
- The quote of the Western altar; "Are you also a prisoner Mordekaiser", likely means that Mordekaiser's affiliation to the Shadow Isles is forced, and he fights this by following his personal objectives, not of the Isles.
- Apart from the altars, the quote (from his old lore) "The common perception is that the encompassing armor protects him, I fear that – for the fragile time being – it actually protects us.", somewhat confirms the Western Altar quote, as his armor might be his prison.
- The quote of the western altar; "Remember who you once were, Hecarim.", suggests that Hecarim was once human, and lived on the pre-cataclysmic Shadow Isles.
- Hecarim marches across Valoran in the name of the Shadow Isles.
- The quote of the western altar; "For the King!", suggests that there is a leader of the isles.
- The Twisted Treeline was the last living forest of Zaun but was retconned to be a location in the Shadows Isles.
The following champion skins were released to celebrate the remake of the Twisted Treeline map. A poll  was conducted to allow the community to decide if these skins would be limited edition, permanent additions to the store, or legacy skins. At the end of the poll, it was decided that the skins were to be available for a short time as Legacy Skins  .
|Elise, the Spider Queen||Origin of power; priestess to the Spider God, Vilemaw|
|Evelynn, the Widowmaker||Place of origin ; deadly assassin|
|Hecarim, the Shadow of War||Probable place of origin; herald for the Shadow Isles|
|Karthus, the Deathsinger||Origin of power; willingly gave his life over to undeath|
|Maokai, the Twisted Treant||Place of origin; Seeks out to punish those who destroyed the Shadow Isles and to restore life to the Isles|
|Mordekaiser, the Master of Metal||Place of origin; possibly the first undead|
|Thresh, the Chain Warden||Origin of power; drags back captured souls to the Shadow Isles|
|Yorick, the Gravedigger||Point of reawakening; ferryman for the undead denizens|
|Lucian, The Purifier||Seeks to purify the Shadow Isles and its denizens.|
|Nocturne, the Eternal Nightmare||Physically manifested in the Twisted Treeline|
|Warwick, the Blood Hunter||Obtained silver from the Shadow Isles|
|Places in Runeterra|
|Field of Justice|
|Continents and Dimensions|