Check out WW2 Bunker Low-poly 3D model purchase 3D model on CGTrader for $2. High-quality mesh by Golden4: 403 polys, 423 vertices. Textured, UV Mapped.
STL (Stereolithography, filesize: 43 KB), OBJ (OBJ, filesize: 46.7 KB), FBX (Autodesk FBX, filesize: 36.8 KB), TEXTURES (Textures, filesize: 7.37 MB)