The longest river in the United Kingdom is the River Severn. Stretching about 220 miles (354 kilometers), it flows through both Wales and England, beginning in the mountainous region of Plynlimon in Wales and eventually emptying into the Bristol Channel. The River Severn has a rich history and significance, serving as a vital waterway for commerce in ancient times. It is also known for its unique tidal bore phenomenon, which attracts tourists and water enthusiasts. The river contributes to the natural beauty of the region and supports diverse ecosystems along its banks, making it a significant natural landmark.