Fallout: New Vegas locations project
The burial mounds consist of many multi-leveled wooden structures with skeletons resting on them. There are several pots containing miscellaneous items spread throughout the areas, usually next to a structure. Exiting from the mounds to the south following the eastern ridge will lead to an upwards path and a hollowed-out rock.
If the player brings Waking Cloud here, she will say, "Please be respectful, these are the bones of our ancestors".