Biskopstunas Castle Ruin — Medieval Archbishop's Castle

The Archbishop of Uppsala and his Castle

At the end of the 13th century, the Archbishop of Uppsala built a fortified castle on land he owned at Tuna, just north of Åkersberga. The castle complex was constructed in stages: the oldest part is a square stone keep, which was later extended with two barrel-vaulted rooms and a narrow single-storey building along the castle's southern side. The location was strategically chosen — from here, one of Roslagen's most important waterways was controlled and the Church's tax collection from southern Roslagen was managed from Tuna.

During the Middle Ages, Biskopstuna was one of Uppsala's four archbishop castles and one of the region's important centres of power. At the Reformation, Gustav Vasa seized Church property and the castle lost its function. The ruin remained, and has since stood guard over the place in silence for more than 500 years.

Sensational Archaeological Finds

Between 2018 and 2023, the Archaeologists, Österåker Municipality and local associations conducted a five-year research project on the site — with results that surprised experts. Beneath the grass around the ruin, a previously completely unknown castle courtyard was preserved, complete with remains of buildings along the edges. Crossbow slits pointing towards the castle testify to the place having been subjected to siege. Finds of household waste, animal bones and everyday objects provide a vivid picture of life in the castle environment 700 years ago.

Art and History Meet

In 2022, Österåker Municipality commissioned artist Elisabeth Ohlson to create a site-specific exhibition in the castle, featuring photographs of archaeological objects from the latest excavations. Guided tours can be arranged. The ruin is a protected historical monument and ongoing conservation work is carried out carefully to preserve the site for future visitors.

Biskopstuna Castle Ruin is located at Allévägen 9, 184 51 Österskär, Österåker Municipality.