Annstead Dunes lie between Beadnell and Seahouses and at the seaward edge are up to 10 metres high. The Trust has fenced areas of the dunes to enable grazing using Exmoor ponies to control marram grass and scrub. Plants to look out for include bloody cranesbill, restharrow and hounds-tongue. The beach down as far as the lower water mark provides an important feeding site for many waders, including redshank, ringed plover, curlew and sanderling.
Annstead Dunes, also known as Annstead Links, consist of a strip of mature sand dunes at the back of the bay between Beadnell and Seahouses. The foredunes at the seaward edge are up to 10 metres high and slope steeply to the beach below. The fixed dunes to the back vary greatly in height and are at their highest towards the southern end of the site, while at the northern end, near Annstead Bridge, they are lower than the foredunes. These fixed dunes once hosted important flora which has diminished through the development of marram grass. A programme of fencing and grazing using Exmoor ponies has been installed and has helped to open up the grass to allow more of the dune flora to thrive, including lady's bedstraw, restharrow and bloody cranesbill. Selectively removing the scrub, concentrating on the sycamore, is also undertaken to preserve the dune conditions. Other plants that occur on the reserve include hemlock and houndstongue, and the site is well used by narrow-bordered five spot burnet and cinnabar moths. There is a colony of common lizards on site. The foreshore beach and Annstead Rocks are outside the boundary of the reserve. However, they are a part of the Northumberland Shore SSSI and have been identified as a potential wetland of international importance under the Ramsar Convention and a Special Protection Area (SPA). The beach down as far as the lower water mark provides an important feeding site for many waders, including redshank and ringed plover. The rock strata of Annstead Rocks dip from north to south resulting in numerous rock pools being formed at low tide which contain a rich variety of inshore marine flora and fauna.