[2] The administrative center of the important Viking settlement Birka (on the neighbouring island Björkö) was situated at Hovgården on Adelsö.

The Adelsö landscape consists of pine-clad rocky hills and moraine ridges dotted with fields and deciduous trees, mainly oak.

The top of Kunsta has an outlook tower offering a great view of the middle of Lake Mälaren.

Influenced by its position in the middle of Mälaren, there is seasonal lag in late winter as the water easily freeze to lake ice.

This is since Mälaren is shallow and surrounded by a lot of land, which in turn raises lake surface temperatures.

The night ferry runs less frequently during the summer months The history of Adelsö began with the Stone Age.

Mälaren, a freshwater lake, did not yet exist, so the skerries that were to become Adelsö lay beneath the Baltic Sea.