This is a paid asset, but now you can download Roman Empire (Built-In) Free.
Detail this asset from Unity Store: Original Link
Roman Empire (Built-In) v1.0
◼ PRODUCT DESCRIPTION ◼
Recreate ancient Rome with the magnificent Colosseum, Pantheon, and other famous monuments. This kit’s Roman-style residential buildings, bridges, squares and fountains will also help you build any modern Greco-Roman city, produced by one of the most powerful Empires of all time!
Modeled by Michal Kozlowski, texturing by Mike Golden, with cover art by Maxx Burman.
◼ A MESSAGE FROM KITBASH3D ◼
Proceed with creativity! You are about to purchase a 3D asset kit that includes elements to set the scene as you build your world, whether it’s for video games, film, television, design, or art. These completely customizable assets will serve as the building blocks to help you create an original environment.
◼ KEY FEATURES ◼
-14 PBR Materials
-4096×4096 Texture Maps
◼ COMPATIBILITY ◼
– Works in Unity 2019.3.13 and above.
– HDRP/Built-In versions are freely upgradeable to Unity customers.