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Caeau Tan y Bwlch Nature Reserve

Location: Capel Uchaf, near Clynnog Fawr, Gwynedd, Wales
OS: SH 431488
What Three Word location: ///lotteries.dusted.birthdays

Habitat: Species-rich neutral haymeadow and rhos pasture

A grass field with trees and mountain at the background
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The Reserve

Caeau Tan y Bwlch lies on the hillside above Clynnog Fawr, at the eastern end of the Llŷn peninsula, Wales. Its name means “the fields below the mountain pass”.

With magnificent views of Anglesey and Eryri/Snowdonia, this botanically important site is full of meadow grasses, sedges, bog mosses and flowers like rare eyebrights. Caeau Tan y Bwlch’s grassland has been traditionally managed without fertiliser or reseeding, leading to this floral feast.

The reserve’s small fields are bordered by clawdd walls – a stone-faced earth bank, where the stone is set on edge almost like the wall of some Medieval castle.

Its history helps explain why the reserve is so important botanically. Its Site of Special Scientific Interest (SSSI) citation commends it as one of the few remaining examples of traditionally managed, enclosed pastures on the Lleyn,


The nature reserve is made up of a number of small, historic field enclosures. The upper fields are species rich hay meadows, and contain a growing population of Greater Butterfly Orchids.

The lower fields are damper, and filled with taller plants like Purple Moor Grass Molinia caerulea and rushes. you will also find sedges, Sneezewort Achillea ptarmica, Marsh Violet Viola palustris and much more.

Species to look out for

  • Cuckooflower Cardamine pratensis – April-June
  • Greater Butterfly-orchid Platanthera chlorantha – June – July
  • Intermediate Lady’s Mantle Alchemilla xanthochlora  – June – September


A map of Caeau Tan y Bwlch


Turn off the A499 from Caernarfon to Pwllheli into the village of Clynnog Fawr. Take the 2nd left and then turn immediately right by the school, signposted to Capel Uchaf.

Continue for about ¾ mile and take the first right uphill – access is concealed and unsigned. Continue up this winding, single-track road for about 1 mile. After a turn to the left, the reserve’s car park is a further 150 metres on your left through a gate.

This nature reserve is owned by Plantlife, but managed by North Wales Wildlife Trust, with whom we work closely.