Oulu is Finland's sixth-largest city, sitting on the shore of the Gulf of Bothnia where the Oulujoki river meets the sea. It is the main city of northern Finland and has a reputation as a technology and university hub — Nokia and other tech companies have long had a presence here.
The city is surprisingly lively for its latitude. The Kauppatori (market square) by the waterfront is the centre of things, with the Tietomaa science centre nearby. Oulu has excellent cycling infrastructure — the bike path network is one of the most extensive in Finland, and even in winter the main routes are kept clear. Within minutes you can be out of the city and into the surrounding countryside of forests, rivers, and rapids.
In summer the days are extremely long (midnight sun in June), and the city hosts the World Air Guitar Championships — one of those Finnish events that is exactly as entertaining as it sounds. In winter the frozen sea and snow-covered islands offer cross-country skiing right from the city centre.