Roman Barrack Block A (Polygon mesh 3D model) is available on CGTrader for $50. Original author: SmartCgArt. Specs: 97032 polys, 93654 verts.
OBJ (OBJ, filesize: 4.79 MB), C4D (Cinema 4D, filesize: 97.2 MB), 3DS (3D Studio, filesize: 44.3 MB), VUE (Vue, filesize: 80.7 MB), DXF (DXF, filesize: 19.8 KB), TEXTURES (Textures, filesize: 399 KB)