Björkö (Ekerö)

Their character and elevated location indicate they belonged to a temporary Bronze Age settlement (1800-500 BC), by people who visited the island for seasonal hunting and fishing.

[3] Birka settlement originated around 800 AD on the shores of the strait separating Björkö and Adelsö, today a pasture-ground known as Bystan covering some 12 ha.

The area is still delimited by the ancient defensive earthwork, which once must have stretched farther south to the hill fort at Borgberget.

[5] Today, large parts of the northern island have been bought by the Swedish government in order to protect the remains.

The area is administered by the Swedish National Heritage Board (Riksantikvarieämbetet), which is attempting to conserve and restore the landscape.