Julma Ölkky, the largest canyon lake in Finland is located close to the southern border of Kuusamo in the Hossa national park. The rock faces rise almost 50 metres from the lake surface. Around the lake are the approximately 10 kilometres long Ölökyn Ähkäsy-trail, and the approximately 5 kilometres long Ölökyn ylitys-trail. Guided boat tours also operate on the lake.