Kielder Forest is a large forest located in Northumberland, England. Covering approximately 250 square kilometers, it is one of the largest man-made forests in Europe. The forest is home to a variety of wildlife, including red squirrels and deer, and features numerous walking and cycling trails for visitors to enjoy. In addition to its natural beauty, Kielder Forest is known for Kielder Water, the largest artificial lake in northern Europe. The area offers recreational activities such as fishing, sailing, and birdwatching. It also hosts the Kielder Observatory, which provides opportunities for stargazing and learning about astronomy.