Hakoinen Castle was an ancient hill fortification, but nowadays there's only some ruins left. Dated medieval, the fortification was situated on a very steep rock by lake Kernaala (Kernaalanjärvi) reminiscent of a hill fort tradition. The top of the rock is 63 meters above the water level in the lake. Today very little remains of the castle. Equally little is known about its origins. One postulation is that it was built by the Swedes as their original stronghold in the medieval Häme area.
The castle was probably built at the end of the 13th century or during the early 14th century. It has been speculated that Hakoinen might have been the fort that was attacked by invading Novgorodian forces in 1311 during the Swedish-Novgorodian Wars, as described in the Novgorod Chronicle.
Eventually Hakoinen was left out of use. Some activity seems to have remained there until 1380s. The castle rock was later a part of a large estate belonging to the bailiff of Häme Castle. According to excavations, the castle was divided into two parts. Lower defensive constructions were mostly made of wood. Constructions on the rock were made of bricks and rocks. The castle probably had one tower.
Although very little remains of the castle, the medieval flora and huge sights from the top of the hill makes Hakoinen castle hill interesting place to visit.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.