Giant’s kettle (Hiidenkirnu)
On the Hakoinen Castlehill, there is also a giant’s kettle, a round shaped opening on the hillside. Melting glaciers from the Ice Age generated rapid streams that could capture a rock in circular motion causing it to grind such formation.
![Giant's kettle Hakoinen Castle hill Janakkala Finland](https://www.janakkala.fi/laurinmaki/wp-content/uploads/sites/2/2016/09/PIC00011-770x578.jpg)