The masonry is made of densely stacked cobblestones of gray and brown colors. Made of seamless material and optimized polygonal mesh.
The actual size is ~4x2 meters. It was created by scanning a real surface using photogrammetry. A closed solid.

Highly detailed PBR material with seamless textures up to 8192x4096px resolution:
JPEG Diffuse, Normals, Roughness; Displacement and AO (not connected)
File MAX contains customized Vray (Corona) material and a seamless square.
faces: 24000

*System units of measurement: centimeters, keep this in mind when importing into a meter-long scene.
*To keep the correct size when importing from FBX for versions MAX 2016 and below, import FBX via the File/Import menu. Input Gamma=1.0 for all textures except diffuseColor.
*In the viewport, the object can be displayed in one color, the normals are completed from the texture at the visualization stage.
*Vray 6, Corona 7 and later