Craig yr Aderyn

Craig yr Aderyn is the site of an Iron Age hillfort, showing two phases of construction. The earlier phase comprises an upper fort enclosure of approximately 0.6 hectares, measuring 100 by 55 metres; the latter, a stone-walled enclosure of approximately 1.6 hectares, measuring 119 by 170 metres. The site has been excavated three times: in 1874, 1921 and 1967. Finds from the Roman period were discovered during the 1874 dig.{{cite web|title=Craig-yr-aderyn, hillfort; Birds Rock |url=http://www.coflein.gov.uk/en/site/302862/details/CRAIG-YR-ADERYN%2C+HILLFORT%3BBIRDS+ROCK/ |accessdate=20 January 2016 |publisher=Royal Commission on the Ancient and Historical Monuments of Wales |date=8 November 2013 }}

Craig yr Aderyn is an isolated hill in the county of Gwynedd, that juts out into the Dysynni Valley. It rises to a height of {{convert|258|m}} above sea level on the south bank of the River Dysynni, near Llanfihangel-y-Pennant. The summit is rocky and the lower slopes are clad in tussocky grassland, heather and bracken.{{cite web |url=http://www.visitsnowdonia.info/craig_yr_aderyn-251.aspx |title=Craig yr Aderyn |author= |date= |work=Snowdonia Mountains and Coasts |publisher=Gwynedd Council |accessdate=26 April 2016 |archive-url=https://web.archive.org/web/20160426231625/http://www.visitsnowdonia.info/craig_yr_aderyn-251.aspx |archive-date=26 April 2016 |url-status=dead }} The two prominent faces of the hill are known locally as 'Y Palis Mawr' and 'Y Palis Bach' ({{langx|en|the large stockade and the small stockade}}).{{Cite book|first=William|last=Davies|title=Casgliad o Lên Gwerin Meirion, yn "Cofnodion a chyfansoddiadau buddugol Eisteddfod Blaenau Ffestiniog 1898"|language=Welsh|year=1900|page=153}}

The site is owned by the Snowdonia National Park Authority, lies entirely within the Craig yr Aderyn SSSI, and is named after the large number of birds, such as the Chough (Pyrrhocorax pyrrhocorax), that roost and nest on the peak.{{cite web |url=http://jncc.defra.gov.uk/default.aspx?page=2081 |title=Craig yr Aderyn (Bird's Rock) |author= |date= |website= |accessdate=26 April 2016}} It is {{convert|2|mi}} from the Cardigan Bay coast.{{cite web |url= |title=Sheet 127 Aberystwyth |author= |date= |work=One inch map |publisher=Ordnance Survey }} The hill is used by a number of species of bird for breeding. The largest inland breeding site for cormorants in Wales is here. Other birds nesting here include the barn owl, little owl, peregrine falcon, common redstart, northern wheatear and common linnet.

The ruins of Castell y Bere, built by the Princes of Gwynedd in the 13th century, are nearby.

The writer Susan Cooper leads her characters to "Bird Rock" in her book The Grey King from The Dark Is Rising Sequence.{{isfdb contents |366203 |The Grey King |first UK edition}}. Retrieved 26 April 2016

The naturalist and scientist Charles Darwin visited this site as a student at Cambridge. He apparently shot seabirds here, according to recollections of a friend, John Maurice Herbert.Herbert, John Maurice. 2.6.1882. [Recollections of Darwin at Cambridge]. CUL-DAR112.B57-B76 (Darwin Online, http://darwin-online.org.uk/)

• List of hillforts in Wales
• List of Scheduled prehistoric Monuments in Gwynedd (former Merionethshire)

• [https://web.archive.org/web/20111006130527/http://www.eryri-npa.gov.uk/conserving/biodiversity-in-snowdonia/current-action/craig-yr-aderyn Snowdonia National Park Authority]

Category:Llanfihangel-y-Pennant

Category:Mountains and hills of Gwynedd

Category:Sites of Special Scientific Interest in West Gwynedd