Tree Gate concept

I re-visited an image that I had in my head when I looked back at some books from my childhood. When I was little, I kept up with the Pendragon series. Within the series, there were gates or portals or some kind that allowed Pendragon to travel to different time periods or worlds. The gates were relevant to the worlds they were a part of. I imagined if there was a forest or jungle sort of world, trees would serves as gates.

Thus this concept: