Llwyn is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales. It consists of two blocks of alder woodland at and, about 2miles south-east of Denbigh and just north of the village of Llanrhaeadr.[1] The site is on the floodplain of the Rivers Clywedog and Clwyd, and includes peat beds and swamps. It was notified in 1983 and 2001.[2] Part of the site, some 9acres, is owned by the Woodland Trust and operated as a nature reserve.[3]