The other day I clicked on a thumbnail at https://maps.farcry.info/ and it switched to a heightmap image of the map:
http://coffey.polygonized.com/FC5/heightMap.png
But I noticed newer maps (mid-february) don't seem to have them. It was a really cool feature, showing heightmap, roads, water and map limits. I wish I had discovered it earlier
I always wished we'd had the ability to import heightmaps into the editor.