Check out Game Ready Scanned Castle Ruins v1 Low-poly 3D model on CGTrader for $5. High-quality mesh by CG-Scan: 68641 polys, 34544 vertices. PBR, Textured, UV Mapped.
OBJ (OBJ, filesize: 6.37 MB), MAX (Autodesk 3ds Max, filesize: 7.13 MB), FBX (Autodesk FBX, filesize: 3.55 MB)