Lake Kemijärvi is the centrepiece of the town and the reason most visitors come. The lake is large and beautiful in the way all Finnish lakes are — still water, forested shores, sky that goes on forever. In summer the midnight sun reflects off the water well past midnight; in winter the lake freezes solid and locals cross it by snowmobile.
The lake offers excellent fishing, particularly for perch, pike, and whitefish. You can rent a rowing boat in town and spend a day exploring the bays and inlets, or swim from one of the sandy spots along the shore. Several marked walking trails follow the lake's edge through birch and pine forest.