When Vuoksi broke through 5,700 years ago, the flowing water eroded a channel into the fractured bedrock, which is nowadays known as Imatra rapids. On the eastern side of the channel is the Kruununpuisto island, where flowing water has eroded potholes into the rocks.

The eastern side of the Imatra rapids channel is steep and its lower section is more worn, because the flowing water eroded the schistose mica gneiss more than the resistant granite above it. The western edge of the channel on the other hand is a gentler slope and descends into the channel in the same direction as the schistosity of the mica gneiss. There are also granite boulders at the bottom of the channel which have detached from the upper part of the eastern slope. On the eastern side of the channel is the Kruununpuisto island, where flowing water has eroded potholes into the rocks during Vuoksi’s early stages, when the river was wider. In the middle of the island is a group of around 50 smaller potholes, while there is a larger double pothole with open sides in the north of the island.

Read more about the geology of Imatrankoski and Kruununpuisto in the Saimaa Geopark signpost (pdf)

Imatrankoski and Kruununpuisto Park are described in the Geological Trail Of Imatra guide (pdf). You can find the route description of the paths in Kruununpuisto and instructions for arrival from the contents of the Outdoor Active platform: Route description of the geological trail of Imatra Kruununpuisto park

There is a culture route through the Vuoksi landscape. You can find information about the Vuoksi culture route here

You can also find more information about the Imatrankoski and Kruununpuisto Park here

Watch a video of the Imatra rapids on Geopark’s YouTube channel

Virtual Imatrankoski rapids show was created in a project called Virtual rapids which was managed by City of Imatra. You can see the Virtual Imatrankoski rapids show from here (The link works only in mobile devices)


Coordinates: x=595347,817 y=6782867,26 (ETRS-TM35FIN)

The above coordinates are working in GPS-devices and karttapaikka.fi services.

The below coordinates are working in Google maps services:

Coordinates: 61.168663265, 28.772491377 (ETRS89 maantieteelliset(~WGS84))


Image: Arto Hämäläinen


  • Suitable for children
  • Viewing point
  • Parking