Swansea Canal was constructed by the Swansea Canal Navigation Company between 1794-1798, measuring some 16 miles long and running from Swansea to Hen Neuadd Abercraf. There were originally 36 locks on the canal to raise it from sea level at Swansea to 375 feet at Abercraf, and aqueducts at Clydach, Pontardawe, Ynysmeudwy, Ystalyfera, and Cwmgiedd to carry the canal across major rivers. The canal was constructed to transport coal from the Upper Swansea Valley to Swansea for export, or for use in the metallurgical industries in the Lower Swansea Valley. The period 1830-1840 saw the development of towns around the canal. Clydach, Pontardawe, Ynysmeudwy, Ystalyfera, Ystradgynlais, Cwmgiedd and Abercraf came into being as industries developed at those locations. The boats were 65 feet long, 7 feet 6 inches wide and carried 22 tons of cargo when fully laden. The last boat built on this canal was ‘Grace Darling’ in 1918 at the Godre’r Graig boat yard. The canal company sold the canal to the Great Western Railway Company in 1872. The tonnage of coal carried on the canal was very high, with 400,000 tons transported down the canal to Swansea in 1888 alone. The canal remained profitable until 1902, when losses were first reported. This decline in revenue and profits was largely due to the competition from its rival – the Swansea Vale Railway. The last commercial cargo carried on the Swansea Canal was in 1931, when coal was conveyed from Clydach to Swansea. Boats continued to operate on the canal after that date but only for maintenance work, with horse-drawn boats last recorded at Clydach in 1958. The Swansea Canal was nationalised in 1947 and became part of the British Transport Commission. 1962 saw control of the canal passed to British Waterways, who remain responsible for the maintenance of the waterway and its structures to this day. In-filling of much of the canal has taken place in the past 50 years, and just five miles of the canal remains in water at the present time, largely from Clydach to Pontardawe where it is now a popular trail and is part of the route 43 of the National Cycle Network. The canal empties from a viaduct into the River Clydach at the point where it joins the River Tawe. A project is underway to dredge the canal and to remove the Japanese knotweed that grows extensively around the Swansea Valley. The canal is an important habitat for water birds who mainly feed on the eels that live there. Local youngsters from Clydach often set up fishing off the banks of the canal to catch the eels.