During the Iron Age, there existed a rich and well-developed society around the mounds of Uppsala. Here, a royal manor stood and people gathered to worship their gods. The site retained its significance as a religious center long after Sweden's Christianization. For a long time, the myth persisted that the mounds in Uppsala contained the remains of ancient pagan deities. Others believed them to be natural hills. In the summer of 1846, the National Heritage Board (Riksantikvarieämbetet) led the archaeological excavation of "Odin's mound" or Östhögen, as it is now called. The excavation revealed that the mound was indeed a grave. However, there were no grand discoveries: only some burned bones and fragments of grave goods. In 1874, Västhögen, previously known as Frö's mound, was also excavated, and it too contained a cremation grave. The mystery of the graves remains. It is certain that important and elevated individuals were buried in the Uppsala mounds. In Östhögen, remains of a helmet and fragments of gold objects were found. In Västhögen, among other things, remains of a sparrow hawk were discovered, presumably a trained hunting bird, a common status symbol among the elite of that time. What was found in the graves were some of the few remaining traces of a large settlement. During the 6th century AD, when the burial mounds were constructed, this settlement thrived. Skilled craftsmen, prosperous agriculture, and a royal manor characterized the area at the peak of its prosperity.

Linnaeus visited the mighty burial mounds, and was fascinated by the meadow flora.