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. [1] [2]
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. [3]
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').
Afon Hepste is a river in Powys, Wales, though partly forming the county's border with Rhondda Cynon Taf. It runs wholly within the Brecon Beacons National Park.
Abercraf is a village in Powys, Wales, in the community of Ystradgynlais and within the historic boundaries of the county of Brecknockshire.
Fan Brycheiniog is the highest peak at a height of 802.5 metres (2,633 ft) in the Black Mountain region of the Brecon Beacons National Park in southern Wales. There is a trig point at the peak and on the edge of the escarpment, and nearby, a stone shelter with an inner seat. It lies just inside the historic county of Brecknockshire which gives the mountain its Welsh name. A subsidiary top, less than a kilometre from the summit along the ridge to the northwest, is the highest point of the neighbouring county of Carmarthenshire. Fan Brycheiniog is also within the Fforest Fawr Geopark designated in 2005 in recognition of the area's geological heritage. The views of the moorland and open country to the north are spectacular when the weather is clear, and reveals the isolation of the range, especially when compared with the more popular Pen y Fan range to the east.
The Black Mountain is a mountain range in South, Mid and West Wales, straddling the administrative boundary between Carmarthenshire and Powys and forming the westernmost range of the Brecon Beacons National Park. Its highest point is Fan Brycheiniog at 802 metres or 2,631 ft. The Black Mountain also forms a part of the Fforest Fawr Geopark.
The River Cynon in South Wales is a main tributary of the Taff. Its source is the rising of Llygad Cynon at 219 m (719 ft) above sea level at Penderyn, Rhondda Cynon Taf and flows roughly southeast, into the Taff at Abercynon in the same district. The water emerging at Llygad Cynon has been traced back to the sink of the Nant Cadlan at Ogof Fawr.
The Afon Pyrddin is a river forming a short section of the boundary between the counties of Brecknockshire and Glamorgan in Wales, United Kingdom. It also forms a part of the boundary of the Brecon Beacons National Park, and the boundary of the unitary authorities of Powys and Neath Port Talbot. The river and its waterfalls are one of the key attractions of the Fforest Fawr Geopark designated in 2005.
The Nant Llech is a minor river in Powys, Wales and which lies wholly within the Brecon Beacons National Park. The name means 'slab stream', presumably in reference to the sandstones across which it runs. Its headwater streams, the Nant Llech Pellaf and the Nant Llech Isaf join forces at Blaen Llech and then continue westwards as the Nant Llech for 3 km / 2 mi to a confluence with the River Tawe just east of the village of Abercraf.
The Afon Haffes is a river in Powys, Wales and is wholly contained within the Brecon Beacons National Park.
The Afon Twrch is a river which rises in the Black Mountain in south Wales. It forms the boundary between the counties of Brecknockshire and Carmarthenshire and, downstream of Ystradowen, between Brecknockshire and Glamorgan.
The Nant Gwys is a river flowing off the Black Mountain in Powys, Wales. Its tributaries Gwys Fawr and the Gwys Fach flow south from Banwen Gwyn and Bwlch y Ddeuwynt respectively and join forces to form the Nant Gwys proper which then flows for about 5 km / 3 mi to its confluence with the Afon Twrch at Cwm-twrch-Uchaf.
Fan Hir is a peak at the eastern end of the Black Mountain in the Brecon Beacons National Park in southern Wales. It is a subsidiary summit of Fan Brycheiniog. It falls within the county of Powys and is also a part of the traditional area of Fforest Fawr. Its Welsh name means "long peak", a fitting description, particularly if seen from the east when its steep eastern face is seen to advantage. It is about 2.5 miles or 4 km long and faces east. Its summit is 2490 feet above sea level. Fan Hir is separated from its higher neighbour to the north-west, Fan Brycheiniog by a col known as Bwlch Giedd, where a path rises from Llyn y Fan Fawr via a stone staircase.
Cribarth is a hill in the Brecon Beacons National Park, Powys, Wales, in the traditional county of Brecknockshire. The summit lies on the broken ridge at an elevation of 428 m (1,404 ft) at OS grid reference SN 831143. To its west is a 426-metre-high (1,398 ft) rounded top at SN 829144 which lies just to the northwest of a mile-long ridge that forms the main bulk of the hill. The ridge attains a height of 423 m (1,388 ft) at its southwest end and this spot is marked by a trig point. Both of these latter high points are adorned by Bronze Age burial cairns.
Mynydd Llangynidr is a mountain in the Brecon Beacons National Park largely in the county of Powys, south Wales. Its southern slopes extend into the northernmost parts of the county borough of Blaenau Gwent. It is named from the village of Llangynidr which sits in the valley of the River Usk to the north of it. It is essentially an undulating plateau rising in the west to a height of 557m at Garn Fawr at OS grid ref SO 123151. A secondary high point is achieved at a point marked by a trig point at SO 147159. To the north the hill overlooks the valleys of Dyffryn Crawnon and Cwm Claisfer, themselves tributary valleys of the Usk. The shallow upper valley of the Ebbw River reaches into the plateau in the southeast whilst the upper reaches of the Sirhowy Valley and its tributary the Nant Trefil define its western margins. A further tributary, the Nant Milgatw, reaches in from the south whilst the sharp edge of Rassau Industrial Estate also defines a part of its southern margin. Passing east across the B4560, the hill merges with Mynydd Llangatwg which has a similar character.
Tair Carn Uchaf is a hill in the Brecon Beacons National Park in the county of Carmarthenshire, Wales. Its summit sits atop a plateau-like ridge at 482 metres (1,580 ft) above sea level and is marked by one of the three huge cairns which give the mountain its name.
Waun Lefrith is a top of Picws Du and is also the westernmost of the Carmarthen Fans, a group of peaks within the Black Mountain of the Brecon Beacons National Park. It lies within Carmarthenshire, Wales. The summit plateau of the mountain reaches a height of 2221 feet above sea level. Picws Du and Fan Foel are the other, higher summits of the Carmarthen Fans. The glacial lake of Llyn y Fan Fach dominates the panorama to the north of the peak. Beyond the lake to the north lies the Usk Reservoir and then the Cambrian Mountains on the horizon. Swansea Bay and the Bristol Channel are visible to the south across the undulating dip slope of the mountain. The Towy (Tywi) valley lies to the west, with Llandovery and Llandeilo as important market towns nearest to the hills.
Picws Du is the second highest peak of the Carmarthen Fans in the Carmarthenshire section of the Black Mountain in the west of the Brecon Beacons National Park in south Wales. The highest peak is Fan Foel immediately next along the ridge and it is a subsidiary summit of Fan Brycheiniog. Picws Du falls within Fforest Fawr Geopark and its prominent summit is marked by a large Bronze Age round barrow at a height of 2457 feet above sea level. Waun Lefrith is the other, lower summit of the Carmarthen Fans situated to the west. The peak overlooks the glacial lake of Llyn y Fan Fach in the cwm below. As the peak sits on the edge of the escarpment on a ridge which juts out into the valley below, the views from the summit are panoramic and extensive. The views to the north are especially impressive when the weather is clear, looking towards the Cambrian Mountains, Mynydd Epynt and Brecon. Swansea and the Bristol Channel can just be seen on the horizon to the south, across the gently falling dip slope. Pen y Fan and Corn Du are distinctive landmarks seen directly to the east across Fforest Fawr.
The Rhiangoll is a river in the Brecon Beacons National Park in Powys, Wales. It rises on the western slopes of Waun Fach, highest point of the Black Mountains and drops steeply down to the west into the north–south valley through which the A479 runs between Talgarth and the hamlet of Tretower and through the village of Cwmdu. It is joined by various minor tributary streams on its left bank including the Ffinnant, Nant yr Ychen, Nant-y-fedw and Nantygarreg, all of which rise on the flanks of the ridge extending between the Pen Trumau spur of Waun Fach and Pen Gloch-y-pibwr. Two tributary streams flowing from Mynydd Troed and Mynydd Llangorse enter on its right bank as does Nant Ewyn east of the village of Bwlch.
The Afon Llynfi is a short river in the county of Powys, south Wales. A tributary of the River Wye, it runs approximately south to north just to the west of the Black Mountains and partly within the Brecon Beacons National Park.
The River Honddu is a river in the Black Mountains within the Brecon Beacons National Park, southeast Wales. Early recorded versions of the name are of the form Hothenei and hodni which are believed to contain the adjective 'hawdd' meaning for example, pleasant or easy. Later forms such as Honddye have undergone metathesis whereby -ddn- became -ndd-.
This article describes the geology of the Brecon Beacons National Park in mid/south Wales. The area gained national park status in 1957 with the designated area of 1,344 km2 (519 sq mi) including mountain massifs to both the east and west of the Brecon Beacons proper. The geology of the national park consists of a thick succession of sedimentary rocks laid down from the late Ordovician through the Silurian and Devonian to the late Carboniferous period. The rock sequence most closely associated with the park is the Old Red Sandstone from which most of its mountains are formed. The older parts of the succession, in the northwest, were folded and faulted during the Caledonian orogeny. Further faulting and folding, particularly in the south of the park is associated with the Variscan orogeny.