Alsnö hus settled
1270 CE.
Shown on the map at 59.361°, 17.535°.
Alsnö hus ('Alsnö House') is the ruin of a palace at the Hovgården settlement archaeological site, located on the island of Adelsö (formerly called Alsnö) in Lake Mälaren in central-eastern Sweden. The ruins are part of the combined Birka and Hovgården UNESCO World Heritage Site.
Text from the Wikipedia article Alsnö hus, licensed CC BY-SA 4.0.