Ystradgynlais

The River Giedd (Welsh: Afon Giedd) is a principal tributary of the River Tawe, Wales. The river runs within the county of Powys and lies almost wholly within the Brecon Beacons National Park (Parc Cenedlaethol Bannau Brycheiniog). This river is perhaps unique in the British Isles in that there are in fact two separate rivers sharing the same name and occupying the same valley but which are not hydrologically connected. The upper Giedd rises on the southern slopes of the Old Red Sandstone mountain, Fan Brycheiniog in the Black Mountain (Y Mynydd Du) and heads south-southwest for about 3 km / 2 mi until, as it enters onto the Carboniferous Limestone outcrop it disappears into its bed. A dry valley continues in the same direction beyond the sinks and, as it crosses the Millstone Grit outcrop, gradually acquires a stream which is joined by others to become the lower Giedd. This separate river flows for about 6 km / 4 miles, passing the small village of Cwmgiedd, to its confluence with the River Tawe at Ystradgynlais in the Swansea Valley. Dye tracing in 1970 revealed that the waters of the upper Giedd which disappear into the ground at Sinc y Giedd eventually re-emerge at Dan-yr-Ogof and do not contribute in any way to the flow of the lower Giedd. The only significant tributary of the River Giedd is the Nant Cyw (translates as 'chick stream') entering on its left bank and whose two tributaries are in turn, the Nant Iar ('hen stream') and Nant Ceiliog ('cockerel stream').

Ystradgynlais railway station served the town of Ystradgynlais in the traditional county of Breconshire, Wales. Opened in 1873 by the Swansea Vale and Neath and Brecon Junction Railway, it was eventually absorbed by the Midland Railway and it closed to passengers in 1932 although the line through the station remained open for freight for some time after that.

Cwmgiedd is a small village beside the River Giedd within the community of Ystradgynlais, Powys, Wales. It lies 22.5 km (15 miles) north-east of Swansea and 253 km (157 miles) west of London. The Silent Village, a 1943 British propaganda film about the destruction by the Nazi occupiers of the Czech village Lidice, was filmed here.

Ynyscedwyn Ironworks is an industrial complex located in Ystradgynlais, near Swansea, Wales. Smelting was first established here in seventeenth century. In the 1820s, with the arrival of George Crane, production was expanded. Crane was the first ironmaster who successfully tried anthracite to a blast furnace in 1837. In 1837, London bankers, Charles Price and Joseph Marryat, invested in the Ynyscedwyn Ironworks. The remaining structures were built in 1872 to house a planned steel mill. Although not completed, the site housed the Ynyscedwyn Tinplate Works.

Ystradgynlais Community Hospital (Welsh: Ysbyty Cymunedol Ystradgynlais) is a health facility in Glanrhyd Road, Ystradgynlais, Powys, Wales. It is managed by the Powys Teaching Health Board.

Mynydd y Drum is a hill on the border between the county of Powys and Neath Port Talbot County Borough, south Wales. The summit of the hill is in Neath Port Talbot (formerly the county of Glamorgan) at 298m and lies towards the western end of a broad curving ridge, the larger part of which is in Powys (former county of Brecknockshire). The eastern half of the hill is currently being opencasted for coal. The hill is sometimes referred to simply as The Drum (a Welsh word, so pronounced 'drim').

Ystalyfera railway station served the village of Ystalyfera, in the historical county of Glamorganshire, Wales, from 1861 to 1950 on the Swansea Vale Railway.

Ysgol Gymraeg Ystalyfera Bro Dur is a Welsh-medium comprehensive school in Neath Port Talbot, Wales. The school provides education to three to eighteen-year-old pupils in Neath Port Talbot and south Powys from three campuses in Ystalyfera and Port Talbot.

Seven Sisters Onllwyn F.C. is a Welsh football team based in Neath, currently playing in the Ardal SW, which is at the third tier of the Welsh football pyramid.

The A4109 road, known as the Inter Valley Road, links Aberdulais with Glynneath in Neath Port Talbot county borough, Wales. The route begins in Aberdulais at the junction with the A4230 and A465 roads; it diverges northwards away from the A465 up the Dulais Valley and crosses through the settlements of Crynant, Ynysfforch, Seven Sisters, Onllwyn, Dyffryn Cellwen and Banwen where it has a junction with the A4221. The road then continues in a southeasterly direction along the Inter Valley Road to Glynneath where it again connects with the A465.

The Afon Twrch is a river which rises in the Black Mountain in south Wales. It forms the boundary between Powys and Carmarthenshire and, downstream of Ystradowen, between Powys and Neath Port Talbot.

Ystalyfera is a former industrial village and community in the upper Swansea Valley, on the River Tawe, about 13 miles (21 km) northeast of Swansea. It is an electoral ward and a community in the unitary authority of Neath Port Talbot, Wales, comprising a resident population of just over 3,000 people, approximately 60% of whom speak Welsh. National Cycle Route 43 passes through the village.