Isle of Quel'Danas (also known as Sunwell Isle or simply Quel'Danas) is a zone north of the Eastern Kingdoms added in patch 2.4, and is one of three areas that make up Quel'Thalas. It is the first outdoor zone added to the game via a patch, and includes many daily quests as well as the last raid and dungeon content released prior to World of Warcraft: Wrath of the Lich King.

The zone's highlights include the Sunwell Plateau, where Kil'jaeden is being summoned; Magisters' Terrace, the final resting place of Kael'thas Sunstrider; and Sun's Reach, a town reclaimed by a combination of Aldor and Scryers forces known as the Shattered Sun Offensive.

Seven thousand years ago, when Quel'Thalas was founded, the magisters of the new elven kingdom created a mystic fountain at a convergence of ley lines on this island off the northern coast of Eversong Woods, utilizing a vial of water stolen from the Well of Eternity sometime before the Sundering. As a result, the island - which became known as Quel'Danas - is also known as the Sunwell Isle. The Sunwell's power allowed the elves to build their cities and shape their land, as well as defend their city; during the Second War, the elven magisters used its power to erect a shield around Silvermoon City to hold off the Horde's invasion.

Separated from the mainland by a channel of the North Sea, this island nonetheless came under attack during the Third War, when the corrupted Prince Arthas Menethil led the Scourge in its slaughtering rampage through Quel'Thalas. Using the power of Frostmourne, Arthas had created a bridge of ice linking Quel'Danas to the mainland, allowing him and his forces to reach the Sunwell Isle and carry out their dark mission to resurrect Kel'Thuzad. The Dead Scar, the path of Blight that splits Quel'Thalas in two — marking the route that Arthas' legions took to the Sunwell — abruptly ends about halfway across the island, near the entrance to the Sunwell Plateau. The Sunwell was befouled with the resurrection of Kel'Thuzad, and the island left to rot as the Scourge continued its relentless march through northern Lordaeron.

After the merciless campaign of Arthas, the essence of the sunwell endured, kept hidden by those who sought to protect it. Today, nearly six years after its destruction, the Sunwell has been reactivated by the power-mad Kael'thas Sunstrider, and is being used as a mystic portal to summon his master, the eredar overlord Kil'jaeden. At the end of the Dead Scar, near the still-shattered structures at its edge, eredar warlocks and wrathguards stand vigilant, and even some remnants of the Scourge's forces remain.

In response to the threat presented by Prince Kael'thas' operations on the Sunwell Isle, the Sha'tar masters of Shattrath City rallied the draenei priests of the Aldor and the blood elf magisters of the Scryers into a unified army, and dispatched them to Azeroth to end Kael'thas' nefarious scheme. This army, known as the Shattered Sun Offensive, has claimed the outpost of Sun's Reach and begins to retake the island from Kael'thas' legions.

Quel'Danas is also the island refuge of the blood elf dragonhawks. It is home to the aeries where the dragonhawks and giant eagles originated and are bred for the elite windriders. Aquel'Luer'Thala is the blood elf in charge of the units stationed on the island.