Check out Cheongju - 3D City Topography Terrain 3D Model Pack 3D model on CGTrader for $499. High-quality mesh by 3D-City-Models.
MAX (Autodesk 3ds Max, filesize: 102 MB), BLEND (Blender, filesize: 8.4 MB), OBJ (OBJ, filesize: 65.7 MB), FBX (Autodesk FBX, filesize: 95.9 MB), MAX (Autodesk 3ds Max, filesize: 102 MB), C4D (Cinema 4D, filesize: 8.4 MB), MA (Autodesk Maya, filesize: 8.4 MB), GLTF (glTF, filesize: 8.4 MB), DAE (Collada, filesize: 66.3 MB), DWG (AutoCAD, filesize: 29.6 MB), 3DM (Rhinoceros 3D, filesize: 147 MB), FBM (fbm, filesize: 139 MB), UNITYPACKAGE (Unity 3D, filesize: 134 MB), SKP (Sketchup, filesize: 136 MB), OTHER (Other, filesize: 60.7 MB), 3DS (3D Studio, filesize: 8.4 MB), DXF (DXF, filesize: 8.4 MB), LS10 (Lumion, filesize: 8.4 MB), RFA (Autodesk Revit, filesize: 8.4 MB), STL (Stereolithography, filesize: 8.4 MB), TM (Twinmotion, filesize: 8.4 MB), UASSET (UnrealEngine, filesize: 8.4 MB), PDF (PDF, filesize: 8.4 MB)