This was done for Rhune Dawn of Twilight. It's the world tree that underpins the cosmology:

Click image for larger version. 

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The genre is nordic stormpunk so a great tree with gear cog world gates fits pretty well. Each of the gear gates has a view into the world beyond, each a version of Midgard with an alternate fate. Here's a few of the gate logos larger:

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Size:  39.1 KB Name:  Niflaeheim.png
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Size:  43.3 KB Name:  Nachtland.png
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For more on Rhune and for the rest of the logos you can read a blog post on it here or the homepage of Rhune: Dawn of Twilight here.

This is a commission piece and so is rights reserved.