Here is a huge pack of grim architecture details and other different assets which you can use to make your own grim environment. All main textures is 4k and inklude all what you need for PBR rendering.
UNITYPACKAGE (Unity 3D, filesize: 1.48 GB), FBX (Autodesk FBX, filesize: 1.25 GB), TEXTURES (Textures, filesize: 1.25 GB), PNG (PNG, filesize: 1.25 GB), JPG (JPG, filesize: 1.25 GB), UASSET (UnrealEngine, filesize: 3.79 GB)