The Great Ga'Hoole Tree, often simply called the Great Tree, is the famous landmark of the kingdom of Ga'Hoole where the Guardians of Ga'Hoole reside. It grows on the Island of Hoole. The tree itself is over a thousand years old, since it sprouted in the time of The Legends Ga'hoole

The Great Ga'Hoole Tree, located on an island in the middle of the Sea of Hoolemere, is a huge, sprawling oak tree where the Guardians of Ga'Hoole and many other owls reside. It is often mentioned in the Legends of Ga'Hoole. Often, owls young and old who have not seen the Great Tree believe it is just a fantasy.

"The Great Ga'Hoole Tree is a most unusual tree. Beyond it's immense size and extraordinary longevity, it's natural history is full of fascinating facts and phenomena."

—Otulissa, A Guide Book to the Great Tree

The Great Tree is an enormous tree that has lived for over a thousand years. It has many hollows for the Guardians to rest in, or for other reasons, like the library a and the parliament. For some reason, when King Coryn brought the Ember of Hoole to the Great Tree for the first time, the Tree stayed a gold color, even during winter when it should have been white.

"You know, the berries taste like what some creatures call milk," Grank added. "Some owls call them milkberries now," Grank said.

—Grank, To Be a King

Milkberries are a popular fruit in the Great Ga'Hoole Tree. The Milkberry is shaped like a teardrop, and grows on vines hanging from the tree. The berries obtained their teardrop shape from the tears of the first Ga'Hoolian King, Hoole, himself. Foods that contain the Milkberry are Milkberry Tea and Milkberry Tart. Those dishes are popular in the Great Ga'Hoole Tree. The Milkberries' color will change with the season. In the time of the silver rain(spring), they are silver, in the time of the golden rain(summer), they are gold, in the time of the copper-rose rain(autumn), they are copper-rose, and in the time of the white rain(winter), they are white. The seasons of the Great Tree are named after the colors of the Milkberries.