Near Rhandirmwyn, Llandovery, Carmarthenshire, Wales

Llyn Brianne Dam & Reservoir

Reservoir

Place photograph

7.7

Wildland

1–2 hours for a visit

Time

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Cost

Big-sky

Feel

HillsRemote countrysideLakesideWalkersPhotographersWildlife loversStargazers

Why it's Wildland

7.7

A vast upland reservoir held behind a 91-metre dam, set high in the Cambrian Mountains. Created in the early 1970s, Llyn Brianne is both a major water-supply reservoir and a striking landscape in its own right.

The scale is the point: a high, open mountain reservoir meeting an immense dam, with forestry and long views around its shores. It feels like a destination for looking outward and walking into the uplands, rather than a place to get on the water.

Big-sky · Dramatic · Remote

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Near Rhandirmwyn, Llandovery, Carmarthenshire, Wales

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The experience

Come for the scale of the reservoir and dam, then choose between a short viewpoint-focused visit and a demanding long circuit. Swimming and boating are not permitted without the required permission, according to Visit Mid Wales; do not assume access to the water.

Things to do

Take in the dam and reservoir

See the large reservoir and its 91-metre dam in their upland setting. Check current access and safe viewing points on arrival.

Walk a section beside the reservoir or through forestry

Visit Mid Wales reports that visitors can walk around the lake and through NRW forestry. It does not provide route details for a short section, so confirm access, conditions and the route locally.

Take on the long reservoir loop

AllTrails describes a 15.5-mile loop with 1,853 feet of ascent, estimated at 6.5–7 hours. It reports muddy sections and some walking beside busy roads; check the route and conditions before setting out.

6.5–7 hours

Make a day of it

Quick escape · 1–2 hours (suggested; not a published duration)

Quick escape: take in the dam and reservoir

01
Use the reported visitor car park as your starting point, after checking current access.
02
Take in the dam and reservoir from accessible visitor areas; confirm route conditions and access on arrival.
03
Allow extra time only if current signage and conditions make a walk appropriate.

Half day · Half day (suggested; route distance and duration not specified for this option)

Make a half day of it: walk by the reservoir

01
Start from the reported car park and toilets, checking current conditions.
02
Walk a suitable section by the reservoir or through the NRW forestry; the supplied source confirms these options but does not specify a half-day route.
03
Turn back when conditions, daylight or your chosen route require.

Verified history

Llyn Brianne was created in the early 1970s by damming the River Tywi and other waterways. Visit Mid Wales describes a reservoir holding more than 64 million cubic metres behind a 91-metre dam; it identifies the site as South Wales’ largest lake by area and Wales’ second-largest reservoir by water volume.

Hidden details

A working water landscape — This is not a natural lake: the reservoir was created in the early 1970s by damming the River Tywi and other waterways. The scale of the dam and stored water is central to understanding the place.

When to go

· No specific recommendation established by the supplied sources; check weather and conditions before visiting.

The supplied sources do not establish a best season or seasonal wildlife spectacle.

The long loop includes muddy sections, for which AllTrails recommends waterproof footwear. Check the weather and current route conditions before setting out.

The route

ascent: 1,853 ft
surface: Some trails may be muddy; route also includes sections beside roads.
distance: 15.5 miles
duration: 6.5–7 hours estimated
difficulty: Hard
route shape: Loop
start point: Not specified in the supplied route source.
parking start: A car park is reported by Visit Mid Wales; whether it is the AllTrails route start is not specified.
shorter alternative: Visit Mid Wales says visitors can walk around the lake and through NRW forestry, but the supplied source gives no shorter route details.

Llyn Brianne Reservoir
Llyn Brianne Dam
Forests and fields around the reservoir

What to look for

01
The contrast between the immense dam and the open upland reservoir
02
look across the water to the surrounding forestry and hills. The supplied sources do not identify specific hidden features.

The story

Water supply and twentieth-century engineering

Best time to go

Check conditions before visiting; no specific seasonal peak is established by the supplied sources.

No best time of day is established by the supplied sources. Check weather, road conditions and current access before setting out.

How long to spend

1–2 hours for a visit; the documented loop is a full-day walk

Perfect for

Walkers · Photographers · Wildlife lovers · Stargazers

Before you go

Website Google Maps

Address

Unnamed Road, Llandovery SA20 0PG

Website

dwrcymru.com

Google rating

4.7 · 509 reviews

Practical information

Opening & access

A visitor car park and toilets are reported by Visit Mid Wales. Check current access and facilities before travelling.

Check before visiting

Parking

Visit Mid Wales reports a car park; current availability and restrictions: Check before visiting.

Check before visiting

Toilets

Visit Mid Wales reports toilets; current availability: Check before visiting.

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Food & drink

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Dogs

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Accessibility

The source row reports a wheelchair-accessible car park, entrance, seating and toilet. Check current conditions and the accessibility of routes before visiting.

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Cost

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Water

Reservoir