|Location||Kokemäki, Satakunta, Finland|
|Type||Impact crater lake|
|Surface area||33.18 km2 (12.81 sq mi)|
|Surface elevation||49 m (161 ft)|
The crater is 5 kilometres (3 mi) in diameter and is completely buried under the lake and is not visible at the surface. The age of the impact structure is estimated to be about 543 ± 12 Ma (million years ago), at the boundary between the Ediacaran and Cambrian periods. There are impactite rocks in the southwestern region from the crater confirming its extraterrestrial origin. At the time of its discovery, only one impact crater (Lappajärvi) was known in Finland.