The Pursiala pothole is one of Finland’s biggest potholes (depth 8m, diameter 2-3m). It was formed around 11,400 years ago when melt-waters streaming in the subglacial river hollowed it out of the migmatite rock consisting of mica gneiss intersected by younger granite dikes.

“Turned stones” have also been found in connection with the pothole – some are migmatites while others are other types of rock such as gabbro. In addition to the pothole, the impact of the glacier can also be seen in the grooves in the rock depicting the direction of glacial movement. Two angles, 320 and 350 degrees, can be seen in the rock, which indicate two glacial flow stages arriving from different directions.

The Kaihu trail through the scenery of the adjacent Kaihunharju esker reaches also to the Pursiala pothole. There are Saimaa Geopark signs at the pothole.

Contents of the big sign at the Pursiala pothole (pdf)

Contents of the small sign at the Pursiala pothole (pdf)

Route description of the Kaihu trail and instructions for arrival

You can also find information about the Pursiala pothole here


Coordinates: x=515596,066 y=6837508,121 (ETRS-TM35FIN)

The above coordinates are working in GPS-devices and for example in service.

The below coordinates are working in Google maps service, which uses geographic coordinates:

Coordinates: 61.670485851, 27.294587986 (ETRS89 maantieteelliset(~WGS84))


Image: Tapani Tervo


  • Suitable for children
  • Parking