Elan Reservoir is a large water reservoir located in the Elan Valley of Wales. It was constructed in the late 19th century to supply drinking water to the city of Birmingham. The reservoir is surrounded by scenic hills and is part of a larger system of reservoirs in the area. The Elan Reservoir is known for its impressive dam, which is a significant engineering feat. It covers an area of approximately 1,000 acres and holds around 40 billion liters of water. The surrounding landscape is popular for outdoor activities such as hiking and birdwatching, attracting many visitors each year.