One of the greatest hikes in the Brecon Beacons National Park is the Llyn y Fan Fach and Llyn y Fan Fawr circular walk. This hugely enjoyable hike scales the mountain peaks of Fan Brycheiniog and Picws Du in the Black Mountain Range massif of south Wales.

In this guide, we’ll talk about what and where the Llyn y Fan Fach and Llyn y Fan Fawr walk is. Then, we’ll talk a little about the hike and the highlights of the trail, as well as provide a GPS map for you to follow. Later, we’ll look at how to get to Llyn y Fan Fach, as well as accommodation options in this part of the Brecon Beacons.

To see footage of Wales’ Llyn y Fan Fach walk in the Black Mountain, please watch our 6 Best Brecon Beacons Hikes Squeezed Into 3 Days YouTube production. For your convenience, when you press play below, the video will start exactly at the section showing the walk. Although, feel free to watch more for some Brecon Beacons hiking inspiration.

For other great hikes in the Brecon Beacons, check out our guides on the Pen y Fan Horseshoe, including the out and back to Fan y Big (guide coming soon). Otherwise, read our Brecon Beacons Hiking post, where we reveal how to squeeze six excellent walks into one epic weekend of hiking.

About Llyn y Fan Fach and Llyn y Fan Fawr

Llyn y Fan Fach and Llyn y Fan Fawr are two lakes nestled in the south of Wales. The name Llyn y Fan Fach means ‘little lake near the peak‘, with Llyn y Fan Fawr meaning ‘great lake near the peak‘. And that’s because, of course, the two lakes are surrounded by a number of mountainous peaks, including Waun Lefrith, Picws Du, Fan Foel and Fan Brycheiniog.

Waun Lefrith was home to a glacier during the last ice age and carved out the bowl in which Llyn y Fan Fach now sits. Llyn y Fan Fawr lies at the base of Fan Brycheiniog, which is the highest peak in the range. Like Llyn y Fan Fach, this lake too was carved out by glacial activity. In fact, Llyn y Fan Fawr is the largest glacial lake in the south of Wales.

The circular Llyn y Fan Fach and Llyn y Fan Fawr walk loops around both of these lakes. The 14km trail passes high above the lakes, traversing through the Black Mountain massif, summiting the peaks of Picws Du and Fan Brycheiniog, before returning to walk along their mountainous bases. 

The Llyn y Fan Fach and Llyn y Fan Fawr walk is easily one of the most beautiful walks in the Brecon Beacons.

Views of Fan Brycheiniog
and Picws Du in the Black Mountain wales

Where Is Llyn y Fan Fach and Llyn y Fan Fawr?

The beautiful lakes of Llyn y Fan Fach and Llyn y Fan Fawr sit within the Black Mountain massif in the stunning Brecon Beacons National Park in south Wales. The trailhead for the hike is in Llandeusant, close to the larger town of Llangadog.

How to Pronounce Llyn y Fan Fach and Llyn y Fan Fawr

The correct Llyn y Fan Fach pronunciation is clinna-van-vack. Llyn y Fan Fawr is pronounced clinna-van-fow-rr.

Black Mountain Brecon Beacons, Wales

The Black Mountain is a mountain range in the south, mid and west of Wales. The Black Mountain in Wales forms the westernmost part of the Brecon Beacons National Park, with its highest peak, Fan Brycheiniog, summited on the Llyn y Fan Fach and Llyn y Fan Fawr walk.

Confusingly, there’s also a Black Mountains range in Wales, as well an actual Black Mountain! The Black Mountains, and the Black Mountain within the Black Mountains (I know, it hurts my head too!) are in the eastern part of the Brecon Beacons National Park. Whereas the Black Mountain Range referred to in this guide, lies to the west.

The Black Mountain massif in Wales is split between the counties of Carmarthenshire and Powys.

Carmarthen Fans

You might have heard of the Carmarthen Fans? The Carmarthen Fans are often misinterpreted as encompassing the entire Black Mountain massif in Wales. However, the Carmarthen Fans only include Fan Foel, Waun Lefrith and Picws Du, with Fan Foel marking its highest point. That’s because these peaks fall on the Carmarthenshire county side. The highest peak on the walk, Fan Brycheiniog, lies in Powys, and so is not part of the Carmarthen Fans.

The Legend of the Lady of the Lake, Wales

The Lady of the Lake in Wales talks about an old folklore legend regarding Llyn y Fan Fach. The legend goes that in the 13th century, a young farm boy saw a beautiful girl emerge from the lake. They agreed to be married, but only on the condition that he would not hit her three times. This seemed very easy to the boy because she was so beautiful, and the two lived happily for years, bringing up a family and tending to the girls magic cattle.

But, over time, the boy did hit the girl three times and so she returned to the lake, with the cattle. The boy was left to bring up their sons, who eventually became known as the ‘Physicians of Myddfai’ and served in the royal court.

It is said that you can see evidence of the girl returning to the water with her cattle by the well-marked furrow running along the edge of the mountain next to the lake.

Beck enjoys views from Fan Brycheiniog
and Picws Du

Llyn y Fan Fach Map

  • Trail Type: Loop
  • Distance: 14.5km
  • Time: 3–4 hours
  • Accumulated elevation gain: 730m
  • Difficulty: Moderate
  • Trailhead: Llyn y Fan Fach Car Park
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The Llyn y Fan Fach and Llyn y Fan Fawr Walk

From the car park, the hike begins along a gravel road, with the cascading Afon Sawdde to your right. You’ll gradually ascend a wide trail until reaching Llyn y Fan Fach. This is when the steep uphill climb begins. A wide trail climbs high towards Waun Lefrith (679m) as you circle above Llyn y Fan Fach. The peak of Waun Lefrith, the first peak of the trail, provides spectacular views of the lake below and the other mountain ranges of Wales’ Black Mountain, like Fan Brycheiniog.

Picws Du

From Waun Lefrith, you’ll follow the rough trail along the escarpment edge high above Llyn y Fan Fach. The path climbs steadily higher toward the peak of Picws Du (749m). From Picws Du, also known as Bannau Sir Gaer in Welsh, you’ll get to enjoy the sweeping escarpment of the mountainside above the lake. The rippled green hillside envelops Llyn y Fan Fach as only a welsh cwtch (hug) can.

Llyn y Fan Fach and Picws Du in the Black Mountain Wales

Fan Foel

From Picws Du, the trail drops steeply down an embankment of around 100m. From this small valley, another climb back up the mountainside is needed to reach Fan Foel (781m). Stood at the peak of Fan Foel, you’re practically bang in the middle of the whole loop trail. Views back towards Picws Du and Waun Lefrith are incredible. Although, from this vantage point, it’s not possible to spot Llyn y Fan Fach any longer. Nor is it possible to get a good look at the unpcoming Llyn y Fan Fawr.

But, up ahead is the biggest peak of the entire walk – Fan Brycheiniog. The trail continues to skirt the top edge of the escarpment as you take the trail towards Fan Brycheiniog. The elevation gain here is fairly minimal, so you’ll get to enjoy the ever-increasing views of Llyn y Fan Fawr as you near the peak.

Llyn y Fan Fach in the Black Mountain wales

Fan Brycheiniog

From the peak of Fan Brycheiniog (802m), you’ll get to enjoy some truly wonderful views from the highest point of the walk. At the base of the gargantuan peak of Fan Brycheiniog is the second of the lakes you’ll visit on this hike – Llyn y Fan Fawr.

From Fan Brycheiniog, the trail begins to descend almost immediately. The trail is steep and winding. Dan and I were unlucky to get caught out in a hail storm during our descent and the exposure on the steep path down felt extreme at times. 

As the path winds its way to the outer edges of Llyn y Fan Fawr, you’ll soon arrive at the base of Fan Brycheiniog peak and by the lake’s edge. The sheltered shoreline is a welcome break from the windy summits and the entire outlook of Llyn y Fan Fawr is beyond beautiful.

Hiking Llyn y Fan Fach and Picws Du

Llyn y Fan Fawr

The trail follows a path along the eastern edges of Llyn y Fan Fawr. Always in the shadow of Fan Brycheiniog on the opposite side. It’s incredible. On a warmer weather day, I dare say we’d have been up for a swim in Llyn y Fan Fawr. I mean, such is the beauty of the lake and its surroundings.

Sadly for us, we encountered another hail storm. So, we broke out into more than our usual speed hike and got a bit of a jog on. Luckily it didn’t last too long and we were able to enjoy the lush rippled hillsides some more.

What’s speed hiking? It’s pushing the pace, covering that trail quicker without losing any of the joy of soaking in your surroundings. Find out more here.

From the far side of Llyn y Fan Fawr, there’s another short uphill section. This leads to a rather boggy crossing through the grassy base of the mountains. Leaving the huge Fan Brycheiniog behind, Fan Foel now takes a prominent stance on the landscape. Truth be told, from this vantage point, the peaks of the Black Mountain massif had a definite Iceland vibe about them. 

Eventually, the walk winds back up on the banks of Llyn y Fan Fach. From here, retrace your steps along the initial rocky road and return to the car park.

Llyn y Fan Fawr and Picws Du

How to Get to Llyn y Fan Fach

As mentioned, the circular walk at Llyn y Fan Fach is located near Llandeusant. The best way to get there is to drive. From the nearest town of Llangadog, the drive time is around 30 minutes.

Of course, you might be travelling from a little further afield. From Carmarthen, you’re looking at a one hour drive. Swansea will be around a 1.25 hour drive and Cardiff a 1.5 hour drive.

There are no direct public transport links to the Llyn y Fan Fach Car Park. Although, you can certainly take public transport to Llangadog. But, from Llangadog, you would need to arrange a taxi to the trailhead.

To that end, driving yourself is by far the most straightforward way to do this hike. If you don’t have access to your own vehicle, then we recommend hiring something. When hiring a car, we always get the ball rolling with a search on RentalCars.com. Booking a car with Rentalcars.com is easy and stress-free, plus they offer an unbeatable free cancellation policy too.

Llyn y Fan Fach Car Park

The Llyn y Fan Fach Car Park can, and does, fill up quickly. The parking area is a decent size but still, there’s not quite enough room during busy periods. Often there’s staff onsite to aid with the congestion. Also, car parking overflows onto the grassy verges surrounding the official car park. But, parking is free. This means you’re not rushed when out on the Llyn y Fan Fach and Llyn y Fan Fawr walk. Parking in the Brecon Beacons in general can be very busy.

The access road leading to the Llyn y Fan Fach Car Park is a single lane with pull in points. It can get very busy and so patience and consideration are essential when entering or leaving. Hiking early or late in the day would help eliminate a lot of the hassle of this drive.

When Is the Best Time to Visit Llyn y Fan Fach?

In terms of crowds, you’re best to visit either early in the morning or late in the afternoon. Dan and I hiked early afternoon and found the trail to be very busy, especially around Llyn y Fan Fach and the walk up to Waun Lefrith. 

Weekends and school holidays are also notoriously busy times for hiking in the Brecon Beacons. For a quieter trail, you should aim to hike midweek.

Llyn y Fan Fach Weather

It’s also a good idea to check the weather before setting out on this walk. Dan and I endured a hail storm and some pretty strong and biting winds during our hike. Although it didn’t ruin the experience, if you’re not keen on extreme weather, you should look to hike on a calmer day.

The lakes are free to hike all year round, which is great! But, if there’s snow on the peaks, you should only consider hiking if you have adequate experience to navigate mountain trails in the snow. This includes the sometimes necessary use of specialist equipment and the knowledge to use it.

You can check the forecast for Llyn y Fan Fach here.

Dan enjoys the views of Llyn y Fan Fach from Picws Du in the Black Mountain Wales

Accommodation For Llyn y Fan Fach

If you want to stay as close as possible to this part of the Black Mountain in Wales, your best bet is to stay in Llangadog. Below, we’ll take a look at the best budget, mid-range and luxury options in the area.

  • Budget – The Red Lion: a stalwart of Llangadog is The Red Lion. The hotel features a bar and restaurant and the rustic rooms are full of old-world charm.
  • Mid-range – Ty Newydd: a comfortable stay at Ty Newydd really sets guests up for the delights of sightseeing in the Brecon Beacons. This quaint B&B has a lovely garden and sun terrace, as well as treating guests to a delicious breakfast.
  • Luxury – Maes Merlin: close to Llandeusant and the trailhead to Llyn y Fan Fach is Maes Merlin. This holiday home boasts three bedrooms, a beautiful garden and a private hot tub. Perfect for relaxing after the Llyn y Fan Fach and Llyn y Fan Fawr walk.

Llyn y Fan Fach Camping

Very close to the Llyn y Fan Fach Car Park is the Wildman Woods Campsite. The campsite here is mostly set up for tent pitches, with a real back to basics feel. You can even start the walk from the comfort of your own tent.

But, the Brecon Beacons National Park is very well set up for campers. So, you’ll find a wealth of options littered throughout the park.

Llyn y Fan Fawr in the Black Mountain Wales

Llyn y Fan Fach Swimming

If you don’t mind the cold water, and the weather is on your side, then it’s perfectly acceptable to swim in Llyn y Fan Fawr. It’s no longer recommended to swim in Llyn y Fan Fach.

Five Hiking Essentials

These are our five hiking gear essentials for the Llyn y Fan Fach walk in the Black Mountain, Wales! For a more extensive hiking gear list, check out our 66 Travel Accessories That You Must Travel With. Alternatively, for a general summary of everything you’d need for a hiking trip to Wales, visit our Ultimate Packing Checklist.

Hiking Essential

Why do you need this?

See it in action

These hiking boots are great for the terrain and conditions of the Black Mountain Range in Wales


This camera is the best compact digital camera on the market. Lightweight, compact and durable, the Sony Cybershot RX100 VII takes high quality photos and 4K videos

Pack for all season in Wales, you'll not regret it

This is a solid backpack for day hikes. It has plenty of space to store everything you'll need

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You should also pack water, snacks and sunscreen. Additionally, the lake’s edges are perfect for a picnic, especially the slightly quieter Llyn y Fan Fawr.

Bonus Tips

  • Pack layers: the weather in Wales, especially the Black Mountain massif can change quickly. Make sure you pack layers and waterproofs for every eventuality.
  • Early start: as mentioned, the Llyn y Fan Fach and Llyn y Fan Fawr walk is an extremely popular hike in the Black Mountain, Wales. Start early or aim for a nice sunset hike to beat the crowds.
  • Breacon Beacons Tours: for some guided tours of other incredible places to visit around the Brecon Beacons, check out some of the fantastic trips on offer by Get Your Guide.

Save or share this post with your hiking buddies before your next trip to Wales!


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