Oulujärvi is a large lake located in northern Finland. It covers an area of approximately 900 square kilometers, making it one of the largest lakes in the country. The lake is situated in the Oulu region and is known for its beautiful natural surroundings, including forests and islands. It is a popular destination for outdoor activities such as fishing, boating, and hiking. The lake is also significant for its ecological diversity, supporting various species of fish and birds. Oulujärvi plays a crucial role in the local economy, particularly in tourism and recreation. Additionally, it is connected to several rivers, including the Oulujoki, which further enhances its importance in the region.