The Community of Glyn-neath (Welsh: Glynnedd) borders the Geopark.  The Waterfalls Centre (SN 901075) stands just within Glyn-neath community.

The lie of the land

Glyn-neath Community ranges in height from 22m above sea level near Resolven to 481m on Hirfynydd (SN 839076)

Solid rocks

The area is underlain by rocks of the Lower, Middle and Upper Coal Measures dating from the Carboniferous period.  These sandstones and mudstones were laid down in equatorial swamps.  Tree ferns and other plants died, were compressed and formed the many coal seams which are now found in the Coal Measures.

The straight character of the Vale of Neath owes its origin to the presence of a major geological fault and associated folds in the local rocks.  Known as the 'Neath Disturbance', this feature extends for dozens of miles across country from Swansea Bay north-east to Hereford and beyond.  It represents an old line of weakness in the Earth's crust and was active during the Variscan orogeny.  Even today minor movements of the rocks along this fault can produce small earthquakes.

Legacy of the Ice Ages

The Vale of Neath was gouged out by glaciers in successive ice ages heading SE from the Brecon Beacons towards Swansea Bay.  It was relatively easy for the ice to erode the shattered rocks which lie along the line of the Neath Disturbance.  The bedrock floor of the valley under Glyn-neath is actually below sea level.  Sand, silt and gravel washed down by rivers at the end of the last Ice Age, and in the thousands of years since, have filled it to its present level.

Archaeology

Abandoned tramways and adits provide evidence of silica mining in the gorge of the Nedd Fechan during the last couple of hundred years.

Maps

Geology

The two editions of sheet 231 'Merthyr Tydfil' of the British Geological Survey’s 1:50,000 map series of England and Wales give full coverage of both the bedrock geology and superficial deposits of the Community area.  BGS publishes a 'memoir' to accompany these maps.

General

The following Ordnance Survey maps cover the Community:

• Landranger sheet 160 'Brecon Beacons' (1:50,000 scale)
• Explorer sheet OL12 'Brecon Beacons National Park/Western area' (1:25,000 scale)

Public transport

Bus services operate along the B4242 road through Glyn-neath and the A4109 Inter Valley Road to Abercraf and the A645 Heads of the Valleys Road to Hirwaun.  The nearest stations are at Neath, Aberdare and Merthyr Tydfil.

See Traveline Cymru for bus and train services including stops, timetables and route-planning information.