As a basis for this interpretation, a brook south of Signhildsberg has been mentioned, or the fact that the estate was surrounded by marshy terrain.

[7] In 1187, Sigtuna was attacked and pillaged by raiders from across the Baltic Sea, possibly from Curonia, or Estonians from the island of Saaremaa (Oeselians),[8][9] or Karelians and Novgorodians,[10] Archaeological excavations have not verified the traditions of destruction of the town.

Normal life in Sigtuna continued until the town started to slowly lose its importance during the 13th century due to navigability problems caused by post-glacial rebound.

Much of the population growth can be related to Stockholm Arlanda Airport (IATA: ARN), situated some 10 km from Sigtuna.

The old church ruins, Viking runestones and the old main street (Stora gatan) are popular attractions for tourists, especially in the summertime.

The small streets with low-built wooden houses lead up to several handicrafts shops and the old tiny town hall (Sigtuna Rådhus).