Krakia?

how exactly would they fit an entire forest, tower and new sky inside of a small pyramid like that? i don't argue that it could be a teleportation device, but saying it's "inside" of something like that is completely farfetched.

If you'll notice, the sky in that picture has crisscrossing lines. This implies a dome around the area in question. The only kind of dome in masteria is the one in the electrophant map. Having a greenhouse inside a dome isn't farfetched at all, especially with the kind of technology seen in the picture.