Oulu

The most populous city in Northern Finland and the third northernmost city in the world with over 100,000 people, after Murmansk and Norilsk. It stands at the mouth of the River Oulu on the northwestern coast, and it has been called the capital of Northern Finland for its size and its position. Wood tar and salmon made it once; information technology makes it now, and it works as one of Europe’s living labs, testing new technology on a city-wide scale. In 2025 the European Environment Agency measured the cleanest air of any European city here.