The above map presents locations that are more difficult to access, which you can visit while exploring The Hissing Wastes.
The dragon guarding the entrance.
Point 1 on the map points to the forgotten tomb. You should know that the entrance is being guarded by a sleeping dragon, at level 20. You can sneak past the beast, though, without waking it up. To open the door, however, you need a key that has been smashed into five parts. All of them are in the chests in the smaller tombs, and you can find them after you solve interactive puzzles. After you obtain all five fragments, the key is assembled automatically and you will be able to access the main tomb. The locations of the tomb, where you find the fragments, have been marked on the map as red dots.