Sundew Credit Chris Wynne

Cors y Sarnau Nature Reserve_Damian Hughes

Cors y Sarnau Nature Reserve © Damian Hughes

Grasshopper warbler

Grasshopper warbler © Richard Steel2020VISION


Sundew © Donald Sutherland

Cors y Sarnau Nature Reserve

Cors y Sarnau Nature Reserve

Common lizard

© Vaughn Matthews

Bog Asphodel

Bog Asphodel © Philip Precey


A special opportunity to see ecological succession in action. As you wander this peaceful wetland, try to trace its journey from lake to woodland.


LL23 7HF

OS Map Reference

OS Explorer Map OL18
A static map of Cors-y-Sarnau

Know before you go

15 hectares

Entry fee


Parking information

Park in the village of Sarnau

Grazing animals

Cattle and sheep, spring and autumn.

Walking trails

Please stay on the footpath at all times. There are areas of deep peat bog and ditches off the way-marked permissive path, and the reserve is best not visited alone.


The ground is uneven and waterlogged all year round. Wellington boots are advisable.


Dogs permitted

When to visit

Opening times

Open at all times

Best time to visit

Spring and summer

About the reserve

Once a shallow lake, Cors y Sarnau is today a nationally important peatland, buzzing with wildlife. At least four species of insect-eating warbler nest in the dense scrub and woodland edge; these are joined by grasshopper warblers nesting in the tall tussock sedges.  All these warblers are summer visitors to the UK, choosing to breed at this wet, insect-rich reserve before returning to Africa and southern Europe for the winter. The site is also home to reptiles, such as grass snake and common lizard (keep an eye out for them on a warm day), cranberry, orchids, insectivorous sundews, dragonflies, woodcock and snipe. A special feature of the reserve is that you can see its development over time in the succession of different plant communities that have colonised the lake over millennia, ultimately becoming wet woodland and willow carr.


Working for wetlands

The reserve is managed to preserve a number of rare wetland habitats which show the site’s ‘hydrosere’ – the transition of plant communities from open water through to mire, fen, bog and wet woodland over peat. These habitats are maintained by keeping water levels at the surface: damming ditches, keeping colonising trees and scrub at bay and cutting and grazing the mire and grassland areas. In 2014, the reserve was extended by purchasing Coed Tŷ Uchaf, a block of conifer plantation adjoining the site. The conifers were clear-felled in 2016 – works to restore native habitats are well underway!

Did you know?

Peat isn’t soil! It’s accumulated bog-moss (sphagnum) that has built up over millennia in acidic, waterlogged conditions. Peat locks up carbon dioxide that would otherwise be released into the atmosphere, making peat bogs critically important to us all in combating climate change.

Park in the village of Sarnau, approximately 4 miles North East of Bala on the A494. Walk back to the main road and cross very carefully (this is a very busy road), then turn Left and walk along the grass verge for 150m. Turn Right at the signposted public footpath into the reserve.

Contact us

Jordan Hurst
Contact number: 01248 351541

Environmental designation

Site of Special Scientific Interest (SSSI)

Cors y Sarnau nature reserve_Guide and Map