Llwyn Onn – Reservoir Walk

Discover Llwyn Onn – Reservoir Walk

Llwyn Onn – Reservoir Walk

This 3.4k circular, shore-lined, walk lets you immerse yourself in the fresh smells of the conifer forest and lapping sounds of the deep blue water.

Llwyn Onn reservoir, built in 1926, covers 150 acres and is the largest of the three in the Taff Fawr Valleys area.

The abundance of fresh clean water provides an ideal habitat for otters, great crested grebes, goldeneye, goosander and coot.

It’s a firm favourite with anglers.  Permits can be purchased at the near by Garwnant Visitor Centre along with tea and cake.

Images courtesy of John Dixon and Nigel Forster




We hope you enjoy the Llwyn Onn reservoir by whatever means you've chosen, but please travel responsibly. Take care of yourself, your surroundings and each other. Download your information leaflets below.

 Mental Wellbeing                                  Enjoy Nature Responsibly                Hiking Safely


Fishing the Reservoirs of Wales



Map - choose and download your map today

To find out more about the trails please download the map below -

If you're travelling through Merthyr Tydfil on the Taff Trail (South to North), then why not download the latest directions map to help you on your way.

Taff Trail Directions Map





Alongside Treasuring our Trails we have a responsibility to ensure we, as custodians, maintain them for generations to come. Please respect the countryside and each other.

Follow the Countryside Code.  Find more information and guidance at the link below.

 Natural Resources Wales Countryside Code

Sustrans Cycle Route Network - Route 8 Merthyr Tydfil to Brecon. Click below to find out more about the cycle networks throughout Wales and the UK.


Ramblers Cymru- Find out more about Ramblers Cymru by clicking the link below.

 Wales Ramblers


The Taff Trail is just one of a series of trails running right through the county borough that encapsulates the area's history complemented by miles and miles of natural beauty. So if you want to take time to stop at one of our amazing adventure attractions, learn about our history, shop, eat, sleep or just take a moment to savour the breathtaking scenery. Merthyr has it all.



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