How were 'The Wizard of Oz' and the 'Epic of Gilgamesh' similar?

That they both deal with quests by the main character is the way in which "The Wizard of Oz" and the "Epic of Gilgamesh" are similar.

Specifically, "The Wizard of Oz" deals with Dorothy Gale's quest to return from the magical lands of Oz to which a Kansas cyclone sends her. The book is the first in the royal histories of Oz series by author and Oz chronicles originator Lyman Frank Baum (May 15, 1856 - May 6, 1919). In contrast, the "Epic of Gilgamesh" represents an one of the early examples of ancient literature, with versions told and re-told between the 22nd and 7th centuries B.C.E. It traces the Urukian King Gilgamesh's epic journey to the Cedar Forest and back home.