Royal Burial Mounds: These burial mounds have been here for 1500 years. This is one of the most important historic settings in Sweden. This area was the chief cult site of the Svear and the seat of their kings. There used to be 2,000-3,000 prehistoric graves in the area, and today about 250 are visible above ground. The three biggest mounds are graves from the 6th century (500s). A Norwegian poem Ynglingatal from the 10th century says that three kings were "howed" (buried in mounds) here during the Migration Period (375-550 A.D.).

In 1874, a large shaft was dug into the side of one of the mounds. A cairn was found, containing a grave with bones, ashes, and molten objects. Parts of combs, ivory, gold threads, a small stylized animal head, a sword hilt of gold with inlaid garnets, and three cameos of onyx from the Near East (present-day Iraq), among other things. These objects suggest that the mound was the grave of a man, perhaps a chieftain.