ISLWYN

district, western Gwent county, southeastern Wales. It was created in 1974 and covers an area of 39 square miles (101 square km). It is bordered by the districts of Torfaen to the east, Rhymney Valley to the west, and Newport to the south. It extends northward along the deep, wooded Ebbw and Sirhowy river valleys to the border of Balenau Gwent district. An Iron Age fort and a medieval castle mound have been discovered north of the town of Risca. Situated on the western edge of the Welsh Marches (border country), the area covered by the district experienced significant Norman influence in the early 1100s. Industry in the valleys did not undergo significant development until the late 1800s and early 1900s, when numerous coal mines were sunk. Celynen South and Celynen North collieries, located just north of the town of Abercarn, were sunk in 1873 and 1913 respectively, and a coal viaduct, stretching 200 ft (60 m) high and 1,500 ft long between two mountain peaks near Crumlin, was completed in 1857. Although some of the coal mines were still operating in the second half of the 20th century, the area's dependence on the iron and coal industry has greatly diminished. The district has become well known for offering a wide range of recreational opportunities, as many of the old mining sites have been reclaimed and much of the district is now devoted to parks and open spaces, including the Ebbw forest with its numerous nature trails and scenic drives. A highway and a railroad run up the River Sirhowy valley from Risca through Crumlin, with the highway branching to the northeast at Nebridge. The town of Blackwood is the administrative seat of the district. Pop. (1991 prelim.) 64,900.