An archaeological testimony to the wide-ranging trade network established back in time by the Vikings.
Birka was also important as the site of the first known Christian congregation in Sweden, founded in 831 by Saint Ansgar.
The town Birka was founded in the 8th century and was an important harbour until the 10th century AD. It is located on Björkö Island. The site includes remains of a fortress, ramparts of a town wall, traces of harbours and thousands of burial mounds.
Hovgården lies on the neighbouring island of Adelsö. It has both Viking and medieval remains, comprising of a church, a brick palace, several burial mounds and a harbour with a runic inscription. Hovgården is believed to have been the site from where kings and chieftains ruled the area.
Birka and Hovgården became a member of Unesco Heritage List in 1993.