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Fan Brycheiniog and Picws Du Walk

By Nia Knott   

on June 11, 2020    4.5/5 (2)

Fan Brycheiniog and Picws Du Walk

Further Details

Route Summary:

Walk to the distinctive Fan Brycheiniog

This walk includes the 2 Washis of Bannau Sir Gaer – Picws Du, Fan Brycheiniog – Twr y Fan Foel

This walk includes the 2 Hewitts of Bannau Sir Gaer – Picws Du, Fan Brycheiniog – Twr y Fan Foel

This walk includes the 3 Nuttalls of Bannau Sir Gaer – Picws Du, Fan Brycheiniog – Twr y Fan Foel, Waun Lefrith

Route Start Location: SA9 1GS is the nearest post code – you’ll have to follow the country lane north turning off the main road opposite the Tafarn y Garreg.

14.88 km 651 m 4.5 hours

Calculate the time using Naismith’s Rule and factor in your own pace.

Activivity Type: Hard Walk

Summits and Places on this Route


Tafarn y Garreg pub in Glyntawe, on the A4067. A traditional pub with delicious and good value home-cooked meals and beer garden. Campsite and on bus route.

Brecon Beacons National Park centre tea rooms and toilets in Craig y Nos, on the A4067. Pay and display parking available.

The International Welsh Rarebit Centre in Defynnog. Amazing traditional welsh food and cakes.


Low cloud is very common in this area, and can come in quickly. Not all of the route has a trail, for some of it there is open boggy moorland so you’ll need good navigation with map and compass. Steep drops off the edge of the ridge. In an emergency call 999 and ask for Police – Mountain Rescue.

Remember that we cannot outline every single hazard on a walk – it’s up to you to be safe and competent. Read up on Mountain Safety , Navigation and what equipment you’ll need.

Parking :

There are a couple of parking lay-bys along the lane – Grid Ref SN 8522.

Public Transport:

There is no public transport taking you to the start of the walk. The T6 bus service runs between Swansea and Brecon – nearest stop is Tafarn y Garreg from where you’ll need to walk a few miles north. Nearest train station is Swansea.

Traveline for UK Public Transport

Recommended Maps


Fan Brycheiniog and Picws Du Walk Ordnance Survey Map and GPX File Download

Download file for GPS

Fan Brycheiniog and Picws Du Walk

Until recently, the peaks of the Western Beacons, also known as the Carmarthenshire Fans, or locally as the Black Mountain/Mynydd Du (not to be confused with the Black Mountains in the East of the Brecon Beacons National Park), were way off the beaten track, known only to the few solace seeking walkers who enjoyed having the hills to themselves. Through social media though, this area has become a bit of a mecca for photographers and droners, and you can understand why. With breathtaking dramatic escarpments gauged out by ice during the last ice age, and twin lakes sitting pretty at their base, there isn’t another landscape like this in the whole of Wales. This is also the home to the famous legend of the Lady of the Lake, a tragic tale of a woman from the welsh ‘Annwn’ or otherworld. This mostly circular walk visits both lakes, and follows the dramatic ridgeline reaching the peaks of Fan Brycheiniog, Fan Foel, and Picws Du.

Fan Brycheiniog and Picws Du Route Descriptions

1. Road to Llyn y Fan Fawr

From the layby, make a short descent down towards the Afon Tawe, and follow the river west until you reach an old stone sheepfold. There are plenty of places to cross the stream here, then you’ll be heading uphill over boggy ground where a path isn’t always visible. You may want to take a bearing but you’ll be walking roughly west – southwest until you reach the lake. You’re heading for the south end of the lake. There is a nice little beach here, just beware of leeches in the summer!

2. Llyn y Fan Fawr to Bwlch Giedd

In the south corner of the lake you’ll reach the bottom of a steep section, where there is a maintained path and steps, badly eroded in places, which you climb up until you reach Bwlch Giedd, the saddle between Fan Hir and Fan Brycheiniog. Don’t forget to look back a few times as you climb – the view on a good day over the lake below is spectacular and you’ll probably welcome the break!

3. Bwlch Giedd to Fan Brycheiniog

Once at the top of the staircase up to Bwlch Giedd, with the lake behind you, you’re heading up the steep steps to your right. Keep the ridge on your right at all times and you won’t go far wrong. There is a well worn path on the top and the ridge offers fantastic views for miles, over to the Black Mountains, Central Beacons including Pen y Fan and north to the Epynt Range. There is a stone shelter at the summit of Fan Brycheiniog which is a great place to stop for a snack.

4. Fan Brycheiniog to Picws Du

Keep following the ridge on the right, flat here until you reach the trig point at Tor y Fan Foel. You’ll then change direction and begin to descend to Bwlch Blaen Twrch. There is a descent option here if you wanted to make the day shorter, but it would be a shame to miss out the second lake. Cross a quite definite stream before making a steep climb up the grassy bank to Picws Du, a lovely shaped hill protruding out proudly with amazing views.

5. Picws Du to Llyn y Fan Fach

From Picws Du again hug the ridge on your right, which travels south-west. When the ridge curves round to the north, begin looking for the path which will take you down a steep slope to Llyn y Fan Fach. The view over the lake on the descent is absolutely spectacular. Head for the dam and shelter at the foot of the lake.

6. Llyn y Fan Fach to Llyn y Fan Fawr

From the shelter at the foot of the lake, you’ll now almost completely retrace the route but along the base of the ridge. This is part of the Beacons Way long distance trail, which hugs the base of the hills closely and contours round all the way back to Llyn y Fan Fawr. If you start going significantly uphill or downhill at this point you’re probably veering off the route.

7. Llyn y Fan Fach to road

Finally, once you reach Llyn y Fan Fach, circumnavigate the lake to reach the far south side where you may want to take a bearing to get you accurately back to the road. Otherwise, head downhill, roughly east, and you’ll reach the Afon Tawe and the sheepfold, cross here then keep heading east back to the layby.

Fan Brycheiniog and Picws Du Walk

Further Walk Images

Nia lives on the Glamorgan Heritage Coast in South Wales and works as a guide leading sightseeing tours and walking holidays across Wales. Nia loves interpreting the landscape, and always looks to include wildlife, geological and historical interest on her walks. When not working, you'll find her out walking with her twin daughters and one-eyed golden retriever, always on the lookout for hidden places and outdoor swimming spots.

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1 thought on “Fan Brycheiniog and Picws Du Walk”

  1. Thank you for putting this excellent route on your website. The description with photographs is very good. However, there are a couple of errors in Part 7 of the description. It refers twice to Llyn y Fan Fach when it should be referring to Llyn y Fan Fawr. I would also take issue with the last two sentences in Part 6 of the description. The first part of the route from Lyn y Fan Fach contours along for about 500m, but then there is a significant climb all the way to the northeast corner of the foot of Fan Foel. I did the walk today under a blue sky, but there was a very strong easterly wind which made tough going over about three quarters of the route. I was nearly blown off my feet a couple of times. Thanks again for the route though.

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