Yggdrasil is an immense and central sacred tree in Norse cosmology. Around it exists all else, including the Nine Worlds.
"The Ash Yggdrasil" (1886) by Friedrich Wilhelm Heine
Yggdrasil (1895) by Lorenz Frølich
"Norns" (1832) from Die Helden und Götter des Nordens, oder das Buch der Sagen
The title page of Olive Bray's 1908 translation of the Poetic Edda by W. G. Collingwood
The world tree is a motif present in several religions and mythologies, particularly Indo-European, Siberian, and Native American religions. The world tree is represented as a colossal tree which supports the heavens, thereby connecting the heavens, the terrestrial world, and, through its roots, the underworld. It may also be strongly connected to the motif of the tree of life, but it is the source of wisdom of the ages.
From Northern Antiquities, an English translation of the Prose Edda from 1847. Painted by Oluf Olufsen Bagge.
The Tree of Knowledge depicted, with Adam and Eve, where the Tree of life is described as part of the Garden of Eden in the Hebrew bible.
Two winged bulls are guarding a sacred tree, on a rhyton from Marlik, Iran, currently at the National Museum of Iran