GIS & Middle-earth, plus free DEM files…
“the Center for Geospatial Analysis at William & Mary, has developed an extensive list of GIS layers of Middle-earth, including a 50m elevation model, roads, rivers, realms and many others. … The data shared below include the complete set of vector layers in wither shapefile or Esri geodatabase format and the 50m DEM of Middle-earth as four quadrants (geo tiff format).”
Based on the remains of the old (now offline) Outerra version of Middle-earth terrain, but substantially improved and overhauled. A 50m DEM is only suitable for a high “eagle’s eye view” or a highly zoomed-out isometric map. That said, AI auto-detailing for low-res DEMs is seeing some progress and will likely see more.
There’s no .torrent, just .ZIPs. I downloaded the smallest .ZIP and loaded the .TIF heightmap to Vue. Here’s the Gap of Rohan with the Fords of Isen, and Isengard at the top of the picture and in the centre of a bowl of mountains. Helm’s Deep is at the edge of the mountains on the bottom-left. A basic map is overlaid. You’ll need maps at massive scanned resolution, to looks crisp when overlaid at this scale. Though the ideal is probably just to get the angle and render, and then over-draw your own hand-drawn isometric map in the Middle-earth style. Although I near that pro GIS systems now have various auto-styles that might get you started there.