Samhain, those are all 8bit/channel images, meaning there are only 256 possible different levels of height. This makes for large potential inaccuracies and possible "stairstepping" in your terrains. They have also been .jpg compressed, which adds artifacts and destroys some fine details that are much more important in a heightfield than in a regular image. That resource is alright for casual use, I suppose, but if you really want to depict an actual place, I strongly recommend against it, as the results will have a high potential for inaccuracy. - Oshyan