This is the bell tower of the church that once was part of a larger cathedral at Uppsala, Sweden. That cathedral became part of the new archbishop’s seat in 1164. It was destroyed by fire around 1245. The centre was then moved downstream to Ostra Aros (east rivermouth), the new Uppsala, and the site for the new cathedral.
Historically this was a central place for the early Swedish kingdom during Viking times (8th to 11th Century). It is believed there was a large temple for Odin, Thor and Frey in the area, but no evidence of its existence has been found.