The hillfort was used by the local Finns proper population until 1170, when it was conquered most likely by the Swedes who possibly used it as a stronghold against Tavastians.
[1][2] The steep hillside supported by fortifications on top of the hill provided a good defensive position.
Earliest defensive structures have been dated to 500 BCE and an outer bailey was in use in the Middle Ages.
[1] The castle was located between two ancient transport routes: Aura river and Hämeen härkätie leading to central Tavastia.
In accordance to the donation charter, Vanhalinna also houses a museum with archaeological finds on display on eras of Varsinais-Suomi, starting from Stone Ages.