This is a paid asset, but now you can download SciFi Platform City for FREE, Please keep in mind this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
For more detail this asset from the Unity Asset Store: Click Here
SciFi Platform City v1.1.2 (Latest version)
SciFi Platform City v1.1
(Tested with Unity version 2020.3.23f1)
SciFi Platform City v1.0
“If possible, please buy the package to support the developer”
With SciFi Platform City you get a tool to create futuristic cities with different levels in a modular workflow. It comes with near 140 prefabs including different blocks to create exteriors & interiors and also elevations & floating platforms to make it spicy. Just add different details from electronics, furniture, etc. Blocks are made to fit among them with a few clicks. You can also use it as FPS or Top/Down environment since rooms are made of separate pieces so you can remove roofs whenever you want. Finally includes high quality materials that allow a high level of customization for the final lookup.
Check out [ASSET INFO] link above for extended info.