Udu, land of the Oogah's.

[Noogah]

Just so we're clear, I'm not downing your map. I think it's imaginative and creative. But there are some things I think you need to reconsider.

Oh don't worry, I didn't think you were. I'm happy to answer any questions, and I'm happy for any suggestions and constructive criticism.

Oh, and I just noticed that I didn't respond to everything you said.

You say it's bathed in moonlight, but isn't it underground? Are the "floating wisps of moonlight" generated by something other than the moon?

Above the Oogah city, there is a hole in the far up in the "ceiling". The Oogahs have a ceremony once a year, where they perform an art created by the Elves. Once a year, the Oogah's perform the ceremony of Memcaeli, to turn the light into clouds, which disperse, filling Udu. It slowly runs out until the next year, when they do the ceremony again.

I find a square to be a very odd shape for a giant, underground cavern. I'd say there would be massive pillars of rock running from the ceiling to the floor as well like when stalagmites and stalactites join as well.

Oh, there are. Many. I just didn't include them on the map. I requested in OP that my taker include those. And, I don't know where you're getting "square" from. Udu has a rather abstract shape.

What are the mines?

That would be a massive collection of rock pillars as you mentioned before, which also happen to be rich in metals and rare elements. The Oogah's have mined these pillars (which are very wide) for centuries, giving it it's uneven and cut away look.

You say the Vast is a volcanic wasteland, but how is that much different than anything else?

Since the vast is the lowest elevation in Udu, it also happens to be the closest to volcanic activity. As such, it is hot, sulfuric, and occasionally has spouts like the bottom of the ocean. This volcanic activity makes the water basin due north warm and swampy. There, things grow because of moisture. But the Vast has no moisture. it is just dry. And, the hot air from the Vast rises and is quickly filled by the heavier and cooler air from farther away, causing unpleasant dust storms.

I'm still waiting for a taker.