Riddle of the Tree

Riddle of the Tree
By Muninn’s Kiss

What is the World Tree?
What is the Axis Mundi?
What is Yggdrasil?
What is Ygg's Steed?
What is Odin's Steed?
What is Sleipnir?
What stands at the Centre of the World?
What bridges worlds?
What is the rainbow bridge?
What is Bifrost?
Where is the Centre of the Compass?
Where is the Circumference?
Who am I?