Inarijärvi — the lake that gives the village and the municipality their name — covers 1,040 square kilometres, making it Finland's third-largest. The shape is irregular, ragged with bays and headlands, and the surface is broken by more than 3,300 islands. The water is exceptionally clear; the lake freezes from November until late May, and breaks up dramatically in May or early June.
The lake is the social and material foundation of the Inari Sámi — the historical winter villages stood on the islands, the spring and summer reindeer migrations followed the shores, and traditional fishing (whitefish, pike, salmon trout) is still important to many families. Boat trips from the village quay run in summer, ice-fishing tours in winter. The view from the Siida shore at midsummer, with the sun never quite setting, is one of the great Arctic sights.