The Severn is the longest river in the United Kingdom, stretching about 220 miles (354 kilometers). It flows through Wales and England, starting in the Cambrian Mountains and emptying into the Bristol Channel. The river is known for its tidal range, which is one of the largest in the world, making it significant for navigation and ecology. The Severn River basin supports various wildlife and habitats, including wetlands and estuaries. It is also home to several towns and cities, such as Shrewsbury and Gloucester, which rely on the river for trade and recreation. The river has historical importance, having been a vital trade route for centuries.