Cemlyn Bay

OS grid ref:- SH329936

Cemlyn Bay is situated about 3 miles from Cemaes on the northwest coast of Anglesey, The bay and the area surrounding it form part of the Cemlyn Nature Reserve which was established in 1971 and is owned by the National Trust. The area is part of a Special Protection Area (SPA) for birds which includes the Skerries. The bay is defined by the headlands of Cemlyn Point and Cerig Brith, the area includes a large lagoon, separated from the sea by a spectacular, naturally-created shingle ridge.

The Anglesey Coastal Path, a 200-kilometre (124 mile) long distance footpath which follows nearly the entire coastline of the island, circles the bay.

Cemlyn Bay

Bryn Aber, the large house situated at the western end of the reserve was bought by the wealthy Captain Vivian Hewitt in the 1930s who built a dam and weir at Cemlyn, changing the saltmarsh area close to the house to become the large lagoon that we can see today. The lagoon serves as a wonderful refuge for wildfowl, providing an ideal nesting site, protected from predators.

Isle of Anglesey

On the islands at the western part of the lagoon is an important tern colony, with the only breeding Sandwich Terns in Wales and the third largest in Britain. Arctic and Common Terns also breed at the reserve, as occasionally does the Roseate Tern. From the vantage point of the tern viewing area on the ridge, visitors to the reserve can experience these rare and elegant birds close-up – chasing and diving in courtship displays; incubating eggs; preening and bathing in the lagoon, or calling to their chicks.

Other breeding birds found at Cemlyn include Black-headed Gull, Ringed Plover, Oystercatcher, Golden plover; Curlew; Dunlin; Redshank; Purple Sandpiper, Shoveler and Shelduck. Grey seals; common lizard and adders may also be sighted.

The shingle ridge supports a maritime plant community; species found there include Sea Kale, Sea Beet, Sea Campion, Thrift and Yellow horned poppy. Sea aster, Sea purslane, Danish Scurvygrass and saltmarsh oraches are found at the edges of the lagoon.


Cemlyn is sign-posted from Tregele on the A5025 between Valley and Amlwch. Although the roads to the site are narrow, there are two car parks adjacent to the reserve