Loketon onkalo is a mysterious, approximately 70-meter-long ravine shaded by rock walls near Pistohiekka in Puumala. One can get to the ravine by a trail starting at Honkajoentie 510 at the southern end of Saarijärvi, where there is a parking lot and a Saimaa Geopark information board. The trail is approximately 1.5 km long and it travels through the ravine to a picnic area located at a scenic cliff's edge. The trail is partly difficult to walk, as there are ladders to climb and part of the path travels along the edge of a rocky slope, where there is a rope handrail for support.

Loketon Onkalo is a Saimaa Geopark geosite.

One can get to the ravine trail by car, but the area is also an easy cycling trip away from both Pistohiekka and Sahanlahti Resort.

Visitors interested in learning more about the ravine and the area surrounding it can also book a guided nature tour of the Geopark site from Guide Tiina.

Kesä 2026