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Countryside Council for Wales
Landscape & wildlife Please note - A new body, Natural Resources Wales has taken over all functions and services previously carried out by Countryside Council for Wales. While the Natural Resources Wales website continues to be developed, some online services will continue to be provided on this web site.

Dyffrynnoedd Nedd a Mellte, a Moel Penderyn

Dyffrynnoedd Nedd a Mellte, a Moel Penderyn is of special interest for both geodiversity and biodiversity. Dyffrynnoedd Nedd a Mellte, a Moel Penderyn is special for its extensive and diverse semi-natural woodland, important populations of several flowering plants and supporting outstanding assemblages of mosses, liverworts and lichens. The old quarry faces and rock outcrops in the vicinity of Pontneddfechan provide excellent exposures of Carboniferous rocks. These range in age from about 325 million to about 315 million years old and detail the changes in environment within a river delta setting. The very bottom layers of the South Wales Coal Measures are exposed here. At Craig y Ddinas and Moel Penderyn a number of faults (cracks along which movement has occurred) and folds can be seen in the rock. The faults, which extend along the Vale of Neath, have been active since Carboniferous times and movement along them continues to cause small earthquakes today. The Mellte and Hepste rivers provide an exceptional example of how geology controls the paths of rivers and the shape of their valley. The numerous waterfalls generally occur when the river crosses a fault, from hard sandstone to softer mudstone.

Dyffrynnoedd Nedd a Mellte a Moel Penderyn SSSI aerial photo

© This orthophotography has been produced by COWI A/S from digital photography captured by them in 2006. Licensed by the Welsh Assembly Government's Department for Environment, Planning and Countryside.

Managing this site

The Forestry Commission and the Brecon Beacons National Park Authority own parts of this site. The remainder is under private ownership. The special features of this SSSI and CCW’s views about site management have been summarised in a Site Management Statement, addressed to the owners and managers of the land. The statement can be found in the resource section below.

Access information

Large sections of this site are designated CROW access land. Other sections are accessible via public footpaths. For detailed maps and information regarding access visit our access map via the resource section below.

Other information

A large part of the site is included in Coedydd Nedd a Mellte Special Area of Conservation. The meaning is ‘the valleys of Nedd and Mellte and Moel Penderyn’ with dyffrynnoedd the plural of dyffryn ‘valley’. The meaning of the river name Nedd is uncertain but ‘shining’ or simply ‘river’ have been suggested. Nedd is almost certainly related to the river name Nidd in Yorkshire. The river name Mellte is also difficult; the river is notable for its unpredictable flow, rocky course and waterfalls and may be connected to mellt ‘lightening’. Mellteu, however, occurs as the name of one of the daughters of Brychan Brycheiniog and the river name may belong to a class of streams and rivers that have been given personal names. Penderyn means ‘bird’s head’ from pen ‘head’ and deryn ‘bird’; Penderyn, probably refers to some apparently bird-like topographical feature such as Moel Penderyn. Moel as a feminine singular noun means ‘treeless hill, hilltop’.




Access map

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The landscapes team [SSSI]
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LL57 2DW
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0845 1306229
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