In Norse mythology, Yggdrasil is the giant Ash Tree that holds together the Nine Worlds, also called the World Ash or World Tree, or Irminsul, Pillar of the World.

It encompasses the Nine Worlds, and is guarded by the serpent Jormungandr. Yggdrasil is one of many variations of the Cosmic Axis or Universal World Tree known to all human cultures.

Yggdrasil is home to many creatures, most notably the serpent or Dragon Nidhogg, lurks in the base, The Eagle , who lives at the tree's peak, and the squirrel, Ratatosk, who carries messges between them. These animals can be viewed as metaphors for the human body.

According to Norse legend, Yggdrasil is where the god Odin hung upside-down for nine nights in order to obtain the magical Rune Alphabet.

According to Norse legend, Yggdrasil is where the god Odin hung upside-down for nine nights in order to obtain the Rune Alphabet. Beneath the roots of the World Ash lies the spring, Mimir, to which Odin sacrificed an eye to gain wisdom.

Modern diagram of Yggdrasil

Pronunciation: ihg drah sill • (noun)

Related Resources:

• Asatru
  The customs, history, and links on Norse Spirituality on About.com.
• Runes- The Alphabet of Odin
  Discover the ancient oracular alphabet of the Norse, the meanings of the Runic characters, and learn how to do a basic divination with Runes.
• Asatru symbols
  Emblems of Norse religion illustrated and explained.