Sometimes referred to as the ‘Sleeping Giant’ owing to its profile when seen from down-valley, this lowly yet rugged mountain has been extensively quarried and is criss-crossed by former tramroads.

OS grid ref SN 827142 (trig point)

The ridge of Cribarth extends along the ‘Cribarth Disturbance’ – an ancient line of weakness in the Earth’s crust which appears here as a couple of tight anticlines (upfolds of the bedrock). A variety of routes lead the walker onto the hill – all are steep!

The terrain on the hill is complex with numerous knolls, shakeholes, disused quarry-workings and natural crags. It makes for great exploration but can be disorienting in mist, especially for the first-time visitor.

The main ridge is a NE-SW aligned limestone anticline or arch whose fractured rock was extensively quarried in the nineteenth century.  It is flanked by steeply dipping beds of Twrch Sandstone (a.k.a gritstone) and an area of rottenstone to the north whose deposits were rapidly exhausted by a workforce under the entrepreneur John Christie.

Dozens of large shakeholes are scattered across the area.  One particular depression at to the west of Cribarth’s ridge, perhaps more accurately referred to as a ‘doline’ may stake a claim to be the largest natural depression in the whole of Wales.


  • OS Landranger 160, Explorer map OL12
  • Geological — ‘Fforest Fawr : exploring the landscape of a Global Geopark’ (1:50,000 from BGS), and
  • BGS 1:50,000 sheet: 231 ‘Merthyr Tydfil’,



  • Pay & display car parking at Craig-y-nos Country Park at SN 840155.
  • Cafe at country park
  • Toilets at country park
  • Entry: free


  • Steep, rocky paths, tricky navigation. Beware! — mountain environment!

Transport links

  • By car — on A4067
  • By train — nearest stations at Neath and Merthyr Tydfil — see Traveline Cymru
  • By bus — see Traveline Cymru; T6 service stops at Glyntawe & Pen-y-cae
  • By bike — a part of the National Cycle Network is being put in place lower down the valley

Other attractions nearby