Lake Øyeren is a large lake located in Norway, primarily in the Akershus region. It is situated near the cities of Lillestrøm and Nittedal and is known for its scenic beauty and rich biodiversity. The lake covers an area of approximately 80 square kilometers and is fed by several rivers, including the Glomma, which is the longest river in Norway. The lake serves as an important habitat for various species of fish and birds, making it a popular spot for fishing and birdwatching. Additionally, Lake Øyeren is part of the Øyeren Nature Reserve, which aims to protect its unique ecosystems and promote outdoor activities for visitors.