Kielder Water is a large artificial lake located in Northumberland, England. It was created in the 1970s as part of the Kielder Water and Forest Park project, primarily for water supply and flood control. The lake covers an area of about 1,000 acres and is surrounded by the largest man-made forest in England. The area is popular for outdoor activities such as hiking, cycling, and birdwatching. Visitors can enjoy scenic views, wildlife, and various recreational facilities. Kielder Water is also known for its dark skies, making it a great spot for stargazing and astronomy enthusiasts.