Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Industrial Factory Abandoned Military Base Set Free.
Industrial Factory Abandoned Military Base Set v1.13
All new updates!
This package contains models of an abandoned industrial factory:
Modular walls, modular roads, modular windows and doors for buildings, containers, debris, litter, barriers, pipes, signs, buildings with interiors, water tower, electrical boxes, street lights, etc. Textures with normal and specular maps. Low poly count. There are also terrain textures and grass textures to use in the terrain tool. This package comes with a playable demo scene.
This package allows you to build a standalone scene of an abandoned factory or military battle field.