The Kennet and Avon Canal is a waterway in southern England with an overall length of 87 miles (140 km), made up of two lengths of navigable river linked by a canal. The name is commonly used to refer to the entire length of the navigation rather than solely to the central canal section. From Bristol to Bath the waterway follows the natural course of the River Avon before the canal links it to the River Kennet at Newbury, and from there to Reading on the River Thames. In all, the waterway incorporates more than 100 locks. The two river stretches were made navigable in the early 18th century, and the 57-mile (92 km) canal section was constructed between 1794 and 1810. In the late 19th and early 20th centuries, the canal gradually fell into disuse after the opening of the Great Western Railway. In the latter half of the 20th century the canal was restored in stages, largely by volunteers. After decades of dereliction and much restoration work, it was fully reopened in 1990. The Kennet and Avon Canal has been developed as a popular heritage tourism destination for boating, canoeing, fishing, walking, and cycling, and is also important for wildlife conservation.