I couldn't find a good screenshot but that cluster of trees is the Forbidden Forest in PS and CoS. Of course they added things but when the kids walk towards it they're walking towards those trees, also Hagrid's hut is down there! The path you see was covered in dirt, if I remember correctly, for the movie.
These statues are all over the tops of the castle towers. They're supposed to be decoys, enemies shooting will think these are real people at shoot arrows at them, leaving them exposed to the real people. You might remember Neville getting caught on one statue? Well, that statue was a prop put in. It isn't really there, I did look for it!