The limestone pavement of this fine hilltop reserve is some of the best to be found in Wales. It is being carefully managed to sustain North Wales' strongest populations of the threatened Pearl-bordered Fritillary butterfly.

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Reserve News

Pearl-bordered Fritillary_Eyarth_14May22_CWilliams
Pearl-bordered Fritillary_Eyarth_May22:C Williams

14th May 2022: Pearl-bordered Fritillaries out in good numbers on the Reserve after a dip in numbers last year due to the cold spring.  On Saturday 47 were seen on the monitored transect. Hopefully numbers will continue to build over the next week or so. Recently cleared areas are serving up a profusion of violets which will hopefully be to their liking!

Species to look out for


    • Pearl-bordered Fritillary
    • White-letter Hairstreak
    • Grizzled Skipper
    • Dingy Skipper
    • Dark Green Fritillary
    • Brown Argus                                            
    • Common Blue                                          
    • Small Pearl-bordered Fritillary

    Notable plants

    • Mountain Melick
    • Moonwort
    • Hound's-tongue
    • Greater Butterfly Orchid


    The Eyarth Rocks reserve is part of Craig-adwy-wynt, one of the richest butterfly sites in North Wales;  32 of the 34 species known to occur in the region have been recorded on this limestone hill-top Site of Special Scientific Interest (SSSI) and most breed there.

    The population of Pearl-bordered Fritillary has grown strongly since 2002 when BC bought and started managing the site. The limestone pavement flora is exceptional and the site provides magnificent views of the area.

    Sheep are grazed on the reserve to help control the scrub growth and break up the bracken cover so that more violets can flourish for the Pearl-bordered Fritillary caterpillars to eat.

    Area: 8.4 hectares



    Grid Reference:     SJ 122 540

    Ordnance Survey:  Landranger 116 and Explorer 256

    Nearest town:         Ruthin, Denbighshire

    Eyarth Rocks reserve is about 4.5 km south of Ruthin in Denbighshire, centred on map reference SJ 122 540

    To reach the reserve: There is limited roadside parking just over Eyarth Bridge SJ 127 553, by the remains of the old rail bridge which used to cross the road. Streetview of Eyarth Bridge parking space. Postcode LL15 2NT.

    From Eyarth Bridge take the public footpath starting at the kissing gate at the road junction by the bridge,  then southwest along the old railway line and up through woodland. At the stile walk up the field to the stile ahead on the right. Cross the lane and follow the path behind the house then take a right into the open clearings. Keep following the path up the cliff to another stile and onto the Reserve.

    By bike: It is about 18 miles by road from Wrexham railway station. 

    By Bus: For buses from Ruthin to Eyarth Bridge please check a website such as Traveline Cymru to get up to date information.


    Site access and safety

    Our suggested access routes involve walks of about 1 km, moderately steep in places, up from the scenic river Clwyd valley. The ground can be uneven and requires strong footwear. The limestone pavement surfaces comprise a myriad of ‘clints’ and ‘grikes’ - narrow crevices that catch the feet of unwary walkers. Please take great care on the western side of the reserve where there is an unfenced cliff edge.

    The hill fort remains are on neighbouring private land, not the reserve.

    Most ticks are little more than an irritation, but a few can transmit Lyme disease, a rare and potentially serious illness which is treatable with antibiotics if diagnosed early. It is therefore important to be informed and take some simple precautions


    Clare Williams (Senior Conservation Officer)

    • Email: [email protected]
    • Tel: Clare Williams: 07974 158814 or Wales Office: 01792 642972