The River Yarrow is a river located in the northwest of England, primarily flowing through the county of Lancashire. It is approximately 20 miles long and is a tributary of the River Douglas. The river is known for its scenic beauty and is surrounded by lush greenery, making it a popular spot for walking and outdoor activities. The Yarrow passes through several towns, including Adlington and Chorley, before joining the River Douglas near Eccleston. The river supports local wildlife and contributes to the area's natural ecosystem, providing habitats for various species of fish and birds.