Ysgard is well known for its heavy connections to the plane-spanning tree Yggdrasil, the World Ash.

Later in Gylfaginning, Just-as-High describes the central tree Yggdrasil.

We went back to the hotel at about half-past ten, to find the courtyard empty save for the thin cat at the foot of the tree Yggdrasil.

For centuries, the tree Yggdrasil has been a constant presence in the lives of the people of Tharsis.

Hel is located under the roots of the tree Yggdrasil.

In Norse mythology, the tree Yggdrasil was a European Ash.

In European mythology the best known example is the tree Yggdrasil from Norse mythology.

The Norns are at the base of the ash tree Yggdrasil (or, according to some versions, above the Bifröst bridge).

At the 'still point of the turning world' the Vikings believed the ash tree Yggdrasil bore the weight of the universe.

A kind of Mirkwood or primeval forest, every tree Yggdrasil, and Frank the Green Man.