Rafiki's Ancient Tree

Rafiki's Ancient Tree, often called The Tree of Life, is home to Rafiki. The tree appears in all Lion King related media. The tree appears to be a large baobab tree. Rafiki is often seen performing various shamanistic tasks there. The trunk of the tree is shown to be covered in paintings, including depictions of Simba, Kiara, and Kovu, all of which were drawn by Rafiki.

Background
Rafiki's Ancient Tree is a tall and thick African baobab tree. Its leaves are always green, as it hasn't been affected at all during Scar's reign. It resides some distance from the Pride Lands and could've been Rafiki's place of origin.

The Lion King
Early in the first film, Rafiki is seen drawing a picture of Simba on the tree's trunk, though he smears it after hearing of Simba's death. Later on, while at the tree, he discovers Simba actually survived. He restores the picture of Simba on the trunk, adding a mane to show Simba's maturity.

The Lion King II: Simba's Pride
In the second film, Rafiki is seen at his tree, conversing with Mufasa's spirit. While talking to Mufusa, he is seen completing pictures of both Kiara and Kovu, telling Mufasa how the two are growing up.

The Lion King 1½
Rafiki appears in a small scene while hanging from his tree. The tree was not seen afterwards.

Trivia

 * Rafiki's tree resembles a baobab tree, a kind of tree native to Africa, where the film takes place.