1 Llangorse Lake car park by Crannog

Llangorse Lake is the largest natural lake in South Wales, the size of around 400 football pitches. Over the centuries it has been known by several names including Llyn Syfaddon and Brycheiniog Mere, but through the ages it has consistently captivated imagination and been the centre of myths, attention and debate.

A key reason for this is the lake’s bountiful nature, where plants, insects, birds and animals flourish in abundance. The lake is what scientists called ‘eutrophic’, which means it is full of nutrients and so able to support a variety of water plants, which in turn sustains a wealth of wildlife.

On this trail we will explore the ways this rich environment has affected and inspired people in different ways at different times.


Llangorse Lake © David Evans, Flickr (CCL)


From the car park cross the little road, heading towards the lake. Follow signs for ‘The Crannog Centre’ to a wooden walkway. Walk along the wooden walkway to the hut with the thatched roof.

2 Crannog

Look over to the tiny island with a cluster of trees on your left. There is something unusual about it. Can you guess what it is?

The island is actually artificial! It was built in the 9th century (between 889 and 893) and is believed to have been a residence of the King of Brycheiniog - the small kingdom in this part of Wales. Such false islands were known as ‘crannogs’ and the main residence would have looked like the hut we are standing next to now.

With all the fields and mountains around, why was there a need to build on the lake itself?

Part of the answer is defence: at this time the kingdom of Brycheiniog was vulnerable to attack from neighbouring Welsh kingdoms (like Gwent) and the English. The king could retreat to his island and block the wooden causeway, making it hard for enemies to attack.

Welsh kingdoms









The other part of the answer though was due to the richness of the environment. Llangorse was teeming with freshwater fish and wild birds, so it provided food for the royal residence. In 1925 archaeologists found a virtually complete dugout boat (a boat made by hollowing out the trunk of a tree) dating from the 9th century here. It shows that the people were skilled at fishing and using the lake to their advantage.

Crannogs were common in Ireland and Scotland, but these are the only remains of one found in Wales. The King of Brycheiniog possibly sent his craftsmen to Ireland to learn how to build one, or an Irish builder may have travelled to Wales. Either way, Llangorse’s crannog shows communication and travel must have been taking place then. You can find out more about the crannog from information boards inside the hut. 


Photograph © Helen Rawling RGS-IBG Discovering Britain

Map of Welsh kingdoms, Wikimedia (CCL) click on map to enlarge


Retrace your steps to the little road and on the other side of it you will see a wooden footpath sign marked ‘Lake Trail’. Follow the sign across the grass, cross the little road and continue following the footpath signs to a footbridge crossing the Afon (River) Llynfi.  

Cross the bridge, turn half left and follow the footpath across the field and over a stile. Continue into the next field and follow the footpath into the middle of the field 

3 Meadow by lake

We are now circling the edge of the lake, though it’s hard to see the water itself because of all the lush vegetation! Huge bulrushes and reeds screen the lake while marsh grass and clover carpet the ground.

As well as attracting royalty, the rich environment has been the source for many myths.

In the 12th century locals believed the lake had magical powers and could predict the future. Gerald of Wales, a famous chronicler of his times, visited in 1188 and noted that green and red currents sometimes appeared in the water. The locals told him these were warnings of impending invasions.

Today we think the coloured currents were probably algal blooms. When nutrient levels in the lake rise (e.g. if heavy rains wash more nutrients into it) then tiny plant-like organisms called algae multiply rapidly. The algae particles can be green, yellow or even red, and they cover the water in a blanket of colour.

The most famous myth was that the lake was home to an afanc: a terrible creature who preyed upon people who fell into the water. The afanc was known as Gorsey and we first hear about him from the 15th century poet Lewys Glyn Cothi:

“The afanc am I, who, sought for, bides
In hiding on the edge of the lake…”

But once again, it may simply be the rich nature of the lake that spawned a monster. Today some researchers believe that what people saw may have been a large pike or even a beaver!


Imagining of an afanc © Sakitaro, Wikimedia (CCL)


Continue along the footpath until you reach another stile, pass over this and walk through a second field. At the end of the second meadow you reach a little bit of woodland and a small wooden footbridge over a ditch with a gate and large wooden carving on the other side.  

4 Damselfly carving

This beautiful wooden carving depicts a giant version of a damselfly, an insect like a dragonfly which lives in watery habitats and feeds on other insects.

Llangorse Lake is the home to the Scarce Blue-Tailed Damselfly, which as its name suggests is blue and rather rare in Britain. The lake’s relatively warm and damp climate plus the abundance of insects provide the ideal habitat for it.

The lake and its surroundings are also home to 23 plant species that are uncommon in Wales, including the White Water Lily. These rare species including the damselfly, as well unusually high numbers of fish and birds, have inspired people to protect and conserve the environment here at Llangorse.

In 1954 it was designated a Site of Special Scientific Interest (SSSI), which means it receives extra protection from development. Such protection is important because if (for example) the land was drained to build houses here, there would be less water and so fewer plants and insects to support the damselfly.  We would risk losing this rare insect in Britain.

Organisations like the Brecon Beacons National Park and the Llangorse Lake Conservation and Management Company work hard to maintain the richness of the lake while allowing visitors to enjoy it. Wind the handle at the base of the carving to hear more about wildlife and conservation efforts here.


Scarce Blue-Tailed Damselfly, Wikimedia (CCL)


Leave the carving and follow the footpath leading off to the left and out of the woodland. Go through more meadow to a wooden gate. Pass through the gate to reach a walkway/boardwalk covered with matting and a large oak tree to your right. 

5 Large oak tree

From the shelter of this old oak gaze out across the reeds and water meadows ahead. All of this could easily have been underwater today!

Although the lake and its surroundings have been popular throughout the centuries, it has faced challenges as people’s needs have changed. In the 1890s a proposal was put forward to flood the lake and several local villages to create a super-reservoir to supply London. This would have raised the water level by 100 feet, meaning the loss of many of these water meadows.

In the late 19th century, rapid industrialisation in cities like London and Birmingham led to a shortage of clean water. People flocked to the cities to work in the new industries and many areas were overcrowded. The use of dirty water meant that diseases like cholera spread quickly and so city councils were desperate for ways to bring in a clean supply.

Between 1893 and 1904 four large reservoirs were built in the Elan Valley, about 30 miles north of here, to provide water for Birmingham. The same thing could easily have happened at Llangorse. It would have destroyed an area around the size of 25 football pitches, home to hundreds of species of plants, birds and animals.

Fortunately the plans fell through and this wildlife haven was safe. Within 60 years it was made an SSSI to ensure it would not face such a threat again. 


Heath Spotted Orchid © Helen Rawling RGS-IBG Discovering Britain 


Follow the walkway 5-10 metres or so until you meet a waymarked post. From here bear slightly left across the field towards a stile and gate. Follow the footpath across another field to a gate at the corner of a wood. Once through the gate turn left and you will see another gate with a sign for ‘Llangasty Nature Reserve and Bird Hide’. Go through this gate and walk down to the lake’s edge to find the hide. 

6 Bird hide

Go into the hide, take a seat and listen carefully.

You can probably hear the rustling of reeds outside. The reed beds around the lake create the perfect habitat for water birds. The beds provide shelter, contain plenty of plants and insects for feeding, and harbour few predators.

Some birds live here all year round – see if you can spot Canada Geese and Grey Herons. Others, such as terns and great crested grebes, use Llangorse as a pit stop during their yearly migrations. In the summer you might even see Osprey here so keep an eye out for large brown and white birds with a hooked beak. Sections of the lake are closed to public access to prevent us disturbing such birds. Rather different from the days we used to eat them!

Our feathered friends are not the only animals taking advantage of this environment; otters are making a comeback. By the end of the 1970s otters had virtually disappeared from Wales and England as they were hunted for their skins or were poisoned by eating fish full of pesticides that had washed from farmland into rivers.

A rich environment can be a problem as well as a paradise though. Remember the ‘magical’ algae we heard about earlier? With so many nutrients in the water, algae can multiply rapidly in blooms that carpet the water surface. This prevents other plants, fish and insects from getting the sunlight and oxygen they need, so they die off.

More recently the zebra mussel has become a similar threat. Originally found in southern Russia, these mussels were accidentally spread to other areas where they reproduce quickly and damage the local environment. Exclusion zones have been set up on the lake to prevent these mussels spreading, while boats brought into Llangorse have to be decontaminated before entering the water. 


Photograph © Helen Rawling RGS-IBG Discovering Britain


Leave the hide, go back through the gate and follow a footpath sign pointing straight ahead. If the path appears to fork, take the right hand branch that leads you towards Ty Mawr Farm. Draw level with the farm, go through a metal gate and follow the main track as it bends right.

As you pass the farm buildings you will reach a track uphill to the left. Start on this but immediately turn right, to cross over a wooden stile by a metal gate with another footpath sign.

200m after the gate pass a big oak tree and you will see a small gate to your right with a footpath sign. Go through the gate and follow the footpath along the side of the hedge and into the corner of the field where there is another gateway (sometimes overgrown so hard to see from a distance).

Go through the gateway and down a little set of steps. At the bottom cross straight over the little path and to the right of a tree you will find another little gate with a footpath sign. Go through the gate into a meadow – the lake should be visible again below.

7 Top of meadow overlooking lake

As the lake comes back into view this is a good spot to reflect on what we have seen today. If you are here in spring or summer the riot of colour in the rolling meadows highlights again what a rich environment we are in. 

Over the centuries this lake and its meadowlands have captured people’s imaginations and interests. In the past this rich lakeside was a source of food and sanctuary for people. The wildlife inspired stories of magical powers and strange creatures. From a royal larder and source of magic, to a nature reserve and outdoor education centre, the thing that keeps us captivated is the sheer variety of species to be found here.

This fertile environment is, however, easily affected by natural and human activities. Wet weather can wash natural nutrients into the lake – and fertilisers seeping in from nearby farmland. Both can cause an explosion of algae in the water, threatening other species. 

Today we seek to protect Llangorse Lake as a place where we, and future generations, can enjoy the diverse variety of wildlife. The key is finding a way to balance enjoyment and conservation; so this continues to be a place where people and nature are integrated rather than isolated from each other. Having explored the lake on our trail today from its fabled monsters to the very real wildlife that flourishes here we hope you better understand this delicate balance.  


Photograph © Geni, Wikimedia Commons (CCL)


Follow the path alongside the hedgerow on the left as it leads downhill back towards the lake. You will re-join the track that you walked in on – look for the boardwalk through the bulrushes and the gate by the oak tree where we stopped to learn about dug out boat. Follow the footpath retracing your earlier steps through the meadows, back round the lake, over the little bridge and back to the car park.

Legends of the lake

Llangorse Lake © Chris Cardew, Flickr (CCL)

Llangorse Lake trail

A short walk exploring the largest lake in South Wales

Llangorse Lake has been known by several names but it has consistently captivated peoples' imagination. It has been at the centre of myths, attention and debate for centuries.

About the size of 400 football pitches, the lake is what scientists called ‘eutrophic’. This means it is full of nutrients and so able to support a variety of water plants, which sustain a wealth of wildlife.

This trail explores the ways the lake's rich environment has affected and inspired people in different ways at different times.

Follow the trail by clicking on the map pins
or downloading the guide below

Location: Llangorse Lake, Brecon Beacons, Powys, Wales
Grid reference: SO1277027088
Start and finish point: Llangorse Lake car park, opposite boat hire hut, nearest postcode LD3 7TR
Keep an eye out for: White and purple Heath Spotted Orchids in the water meadows, and boggy patches!

Llangorse Lake trail credits

Thank you to - 

Helen Rawling for creating and photgraphing this viewpoint

Caroline Millar and Rory Walsh for advice and edits

David EvansGeni and Sakitaro for photos reproduced under Creative Commons Licenses

Lily Alsop for putting together the written guide 


"If the natural prince of the country, coming to this lake, shall order the birds to sing, they will immediately obey him"

- ancient saying about Llangorse Lake, recorded by Gerald of Wales in the 12th century