Hi!
Here is a map of a small part of the Great Valley which I created for the land before time story I'm working with at the moment. Unfortunately the quality suffered a bit from transforming the original bitmap into a jpeg. The map shows the south-eastern corner of the Great Valley. There are only two landmarks to be found in this map, which you will know from the movies. The gap in the Great Wall you can see on the upper right is the one through which Ali's herd entered the Valley in LBT 4, and right above it you can see "Lookout ledge", the ledge from where Littlefoot first spotted the herd.
On second thought, you also know that rocky wall that stretches into the Valley north of the ledge, but you know it only from its northern side (actually it should consist of a number of several rounded rocks, and it ought to be longer to match the view we got of it in the original movie). Because of the many landmarks we saw in the Great Valley during the sequel, but which we didn't see when Littlefoot was gazing over the Great Valley in the original movie, I assume that what Littlefoot saw in the original movie was only a fraction of the Valley which was surrounded by rocky walls (with very large gaps between them), so almost like a Valley inside the Valley. I drew a map depicting that theory as well, but I can't find it at the moment. It is the map I mentioned before, the one I never finished.
