|OS map required
This really is in the middle of nowhere on open moorland. Crossing several streams and it’s boggy.
Head out to the Usk Reservoir and use the car park just before the bridge Pont’ar Wsyg.
Follow the track beside river Usk in a southerly direction away from the reservoir.
After 200m or so of this the river forks. Cross the river and follow the right fork.
After 400m or so the river forks again. To your right is the Usk, on your left is the Nant Tarw. Cross the Nant Tarw.
Hopefully you are now between both rivers and ahead of you is rising land. Walk in a southerly direction keeping closer to the stream on your left (Nant Tarw) rather than the Usk on your right.
400m ahead you will hopefully reach a ruined (robbed) circular stone cairn. It is a good landmark and the stone is bare of grass and some 16m by 11m (0.3m in height).
The stone circles are over to the east of the cairn on a plateau.
Behind the hill you are walking along are two mountains (with dramatic scarps: Picws Du and Fan Brycheiniog). If you reach a point where the hill you are on is obscuring these two peaks: you have gone too far and missed the stone circles.
If you reach a point where you are having to cross several streams running down from the hill to the river Nant Tarw: you have gone too far and missed the stone circles.
At the top of the hill is a fence, so it is unlikely you will wander off and die of exposure on the Black Mountain (although there is supposedly a stone circle up there SN 823232 around 600m up Fan Brycheiniog).
It is worth considering when at the circles that if you stand facing north: in the wooded hill north of the Usk Reservoir are two standing stones; another two at the eastern end; another two stone circles (Mynydd Bach) on the hill beyond that just below Y Pigwn. To your right less than 2km away is the standing stone Blaenau Uchaf. Behind you 3km or so away is another stone circle (as previously mentioned, but I cannot find any information on it). Infront of you is a ruined stone cairn (antiquarian accounts indicate 5 or 6 erect stones once defined its circumference).
Nant Tarw consists of a pair of small Bronze Age stone circles 110m apart and intervisible with each other.
The western circle is the higher of the two, slight ellipse of 15 stones with a diameter of 19m. Stones vary in height from nothing to 1m. A guide states that there are entrance gaps at west and east, but because the stones are small and some missing it’s not that obvious. It is comprised of glacial boulders and Old Red Sandstone slabs.
Between the two circles is a large fallen stone 2.6m long by 1.5m wide.
The eastern circle is similar in size (slightly larger at 21m and also an ellipse) and has 18 visible stones. The stones vary in height from nothing to 1.25m, one of the fallen stones would have been higher than that. Again the guide I consulted suggests two entrance gaps, this time in the southeast and southwest sections. Similar stones used to the western circle
Many of the stones are very low. To give you a better idea, many of the guides state that the visiblity of stones is dependent on weather conditions on the ground and plant growth: we are not talking Avebury here by any means. It is a fair slog across open moorland and streams to reach the site.
That said on the day I visited the weather was fair, the scenery majestic and I had the mountains to myself all day. I did run out of water though, so be prepared to be self-sufficient when you're out there.
Posted by elderford
6th August 2003ce
Edited 7th August 2003ce