Y Byddwn

Reserve Information


From Brecon follow the A40 east for 2 miles, and turn left, then right for Groesffordd. Just before entering Groesffordd turn right again for Llanfihangel Tal-y-llyn. After half a mile, a wide verge on the right indicates the starting point for foot access. Proceed through the left hand gate and walk along the disused railway line for half a mile until you come to the reserve entrance gate.

Nearest town: Groesffordd. Post code LD3 7SU.

SO 087 277


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Public Transport

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Opening Times



0.2 hectares

Walking Information

The reserve is an open access reserve, you are allowed to visit the reserve on foot for your quiet enjoyment of the wildlife present. A path runs the length of the reserve along the old railway bed.


Unsuitable for wheelchairs.

Geology Trail


Park considerately on side of track, and walk along course of old railway to site.


Please keep dogs under close control.

Grazing Animals


Factsheets and Guides for Your Visit

Y Byddwn

This small nature reserve, which gives excellent views of the Brecon Beacons, is a section of the former Brecon to Merthyr railway line. Originally built as the Brecon to Hay-on-Wye tramroad, it became a railway in 1864. The line closed in 1964 and became a nature reserve in 1980.

The woodland beyond contains a seasonal pond that dries up in summer.

The reserve annually hosts many species of woodland birds such as treecreeper, goldcrest and bullfinch while summer migrants include chiffchaff, blackcap, spotted flycatcher and redstart. The meadow is home to many interesting moths and other insects and a species list of all flora and fauna is available.

Much work since 2017 has been carried out at the reserve to increase its potential to encourage a more diverse flora and fauna and access to the reserve will also be easier in 2019.



The pond at Y Byddwn

What to look out for

To the left of the flower-rich grassland at the site entrance is a row of trees that include oak, beech, wych elm and mountain ash. Watch out for mallard, grey wagtail and dipper.

The disused railway is an important feature in the landscape for commuting and foraging bats, including the rare lesser horseshoe bat.

In the spring and summer the repetitive call of the chiffchaff, the musical warble of the blackcap and the soft, descending call of the willow warbler can be heard.

You can download a list of the species identified as of 2018.

Species and habitats

Brownfield, Hedgerows, Lowland Meadows, Lowland Mixed Deciduous Woodland, Ponds
Azure Damselfly, Black Knapweed, Black-kneed Capsid Bug, Blackcap, Candlesnuff fungus, Cardinal Beetle, Chiffchaff, Collared Earthstar fungus, Common Blue Damselfly, Common Carder bee, Common Damsel Bug, Common Shrew, Cream Spot Ladybird, Dog Sick Slime Mould, Early-purple Orchid, Forest Bug (Shield bug), Green Shield Bug, Hawkweed Oxtongue, Hawthorn Button Top Gall, Hornet, Marmalade Hoverfly, Meadow Grasshopper, Moschatel, Nuthatch, Oakmoss Lichen, Pompilid Wasp, Pygmy Shrew, Red Tailed Bumblebee, Redstart, Rhinoceros Beetle, Robins Pin Cushion, Scarlet Elf-cup Fungus, Soldier Beetle, Southern Hawker Dragonfly, Spotted Flycatcher, Tawny Mining Bee, Tree Bumblebee, Treecreeper, Turnip Sawfly, Twayblade, Water Cricket, Welsh Chafer, Whirligig beetle, Yellow Archangel, Zigzag Clover

Local Warden’s Blog

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    Paths, gates and rock falls, the Brecknock team have been busy this Spring! During April and early May we have been doing some repairs on the Brecknock Nature Reserves using materials purchased with the NRW Strategic Partnership grant.  A 12’ gate was replaced at Glasbury Cutting and firmly shut to keep the horses off the reserve.  ...

Nature Reserve Map