The Alna River is a river located in Norway, flowing through the municipality of Alna in Oslo. It is approximately 20 kilometers long and is known for its scenic beauty and natural surroundings. The river is a tributary of the larger Glomma River, which is the longest river in Norway. The Alna River is an important ecological area, supporting various wildlife and plant species. It also serves as a recreational spot for locals, offering opportunities for activities such as fishing and walking along its banks. The river plays a significant role in the local environment and community.