The Boughs of Azshara were originally located in what was known as Suramar, the religious capital to the Kaldorei and Quel'dorei (or Highborne elves, which was the name given to those magic users close to the Queen Azshara, ruler of the original elven homeland). The Boughs of Azshara were twin Aspen trees, sacred to all Kaldorei and Quel'dorei, as well as some followers of Elune. Now they are twin stumps sitting somewhere on the Broken Isles off the eastern coast of Kalimdor.
The Boughs were lost to all of civilization when the capital of the elven people, Zin-Azshari, sank to the bottom of the ocean with many other significant elven sites. However, roughly ten thousand years later, the warlock Gul'dan accidentally raised the Boughs of Azshara alongside the Tomb of Sargeras, which had formerly been known as the Temple of Elune. The Temple of Elune and Boughs of Azshara had both been located in Suramar. These different, newly discovered historical sites would become known as the Broken Isles, a scattered group of islands off the eastern coast of modern day Kalimdor, closer to the twisting Maelstrom, the physical remainder of the Well of Eternity and the marker of Queen Azshara and cherished Quel'dorei's watery grave.
Twenty years after Gul'dan had inadvertently raised the Boughs, and ultimately caused his own death, Illidan Stormrage had managed to break free of his earth-bound prison. Upon doing so, he headed straight for the Broken Isles and Tomb of Sargeras, seeking new power that he believed to exist there. He would not do so without some repurcussions, as his jailer, Maiev Shadowsong, was hot on his tail. Upon reaching the Broken Isles and seeing what stood before her, Maiev reminisced on many things, one of which was what was left of the former Boughs of Azshara. Commenting to Naisha the Huntress and the other members of her hunting party, "Great trees once stood in this place, twin aspens called the Boughs of Azshara. To look upon them was to know true peace, true fulfillment. Now they are gone, along with the hopes and dreams of a generation."
Other than this, nothing else is known about the Boughs of Azshara to date.