The city lives under a fake sky dome in a canyon. Outside is too polluted to be habitable. The giant vertical structure attaching to the cliff contains water and air filter system, generate energy, and also house thousands of civilians.
Canyon City , Tu Bui on ArtStation at https://www.artstation.com/artwork/n1w51
“The Mriya” by Min Seub Jung.
Mass Effect 3 Citadel - What's not to love from modernistic worlds, to a green environment
Orbital Lift by IllOO on deviantART
70s sci-fi art: boomerstarkiller67: The Future - art by Shusei...
Personal work. Modeled and texturized in 3dCoat. Render in Keyshot. Retouches, phototextures and finishing in Photoshop.