Check out Simple Poly City - Terrian Low-poly 3D model on CGTrader for $5. High-quality mesh by Cad-Saad.
MA (Autodesk Maya, filesize: 762 KB), OBJ (OBJ, filesize: 320 KB), FBX (Autodesk FBX, filesize: 653 KB), GLTF (glTF, filesize: 543 KB), ZTL (Zbrush, filesize: 99.1 KB), STL (Stereolithography, filesize: 165 KB), BIP (KeyShot, filesize: 267 KB)