Øyeren is a large lake located in Norway, primarily in the Viken county. It is known for its scenic beauty and diverse wildlife, making it a popular destination for outdoor activities such as fishing, boating, and hiking. The lake is also an important water source for the surrounding communities. The lake has a surface area of approximately 84 square kilometers and reaches a maximum depth of about 60 meters. Øyeren is fed by several rivers, including the Glomma, which is the longest river in Norway. The area around the lake features various nature reserves, promoting conservation and recreational opportunities.