This build is a replication of the Cloud City of planet Bespin from Star Wars Episode 5: Empire Strikes Back
It is as tall as possible without mods, going up the entire world height.

The size of it is about:
153x319x153

NOTE: I was building it going off of a 3D model I found online.
STL file Star Wars Bespin - Cloud City ⭐・3D printing idea to download・Cults (cults3d.com)
I didn't buy or download the 3D model, I was building using the screenshots are references. All credit to the original artist. Without them it wouldn't be possible.

Building this I was trying to make it as closely resemble it's original design in the movie as my building skills would allow it.
However it does not have the antennaes on it's bottom from which Luke was hanging onto before being rescued. It was practically impossible to pinpoint where they were supposed to be placed so I left it like that.

Built mostly using WorldEdit mod.

THERE IS UNFORTUNATELY NO DOWNLOAD LINK. I WOULD ADD IT IF THE SITE ALLOWED ME TO. IT JUST WON'T WORK. SORRY.