Zoe has given out a lot of the history of the dam. Let's just add a bit of local information to say that this is a hidden gem of a reservoir. Though well known by locals, it is still an under-visited location. There are lovely walks to be had either around it or through the adjacent forests, there is a cafe and a roadside service van with refreshments on the way around; and the trails are great. The forest views, quaint foot bridges, and views out over the water make it a very scenic area.

Zoe Evans

March 29, 2022

Hiking

Llwyn-on Reservoir (or Llwyn Onn Reservoir) is the largest and southernmost of the three reservoirs in the Taf Fawr valley in South Wales. Cardiff Corporation Waterworks obtained an Act of Parliament in 1884 to authorise construction of the reservoirs, to increase the water supply for Cardiff, but construction of Llwyn-on Reservoir did not start until 1911 and was completed in the 1920s.

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Best routes to Llwyn-on Reservoir

4.3

(32)

252

hikers

1. Llwyn-onn Reservoir loop — Bannau Brycheiniog (Brecon Beacons) National Park

5.43km

01:26

50m

Easy hike. Great for any fitness level. Easily-accessible paths. Suitable for all skill levels.

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Easy

4.3

(33)

253

hikers

2. Llwyn-on Reservoir loop

5.50km

01:26

40m

Easy hike. Great for any fitness level. Easily-accessible paths. Suitable for all skill levels.

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Easy

4.6

(12)

hikers

3. Garwnant Visitor Centre – Llwyn-on Reservoir Dam loop from Forest Visitor Centre

9.02km

02:28

140m

Moderate hike. Good fitness required. Easily-accessible paths. Suitable for all skill levels.

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Moderate

Details

Informations

Elevation 270 m

Weather

Today

Tuesday 3 February

4°C

1°C

87 %

Additional weather tips

Max wind speed: 22.0 km/h

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Location: Merthyr Tydfil, South Wales, Wales, United Kingdom

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Llwyn-on Reservoir

1. Llwyn-onn Reservoir loop — Bannau Brycheiniog (Brecon Beacons) National Park

2. Llwyn-on Reservoir loop

3. Garwnant Visitor Centre – Llwyn-on Reservoir Dam loop from Forest Visitor Centre

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