It lies between the River Nith and the Lochar Water, and consists of a variety of wetland habitats including bare mud and sand, merse and marshes, and is fringed by neutral grassland on the landward side.

[4] The NNR covers an area of 82 square kilometres (32 sq mi) and is an internationally important wintering site for waterfowl and wading birds.

[7] Management of the site seeks to balance the human activities (fishing, wildfowling and farming interests) with those of nature.

[10] Caerlaverock is also home to the UK's most northerly population of natterjack toads , which live in shallow pools on the landward side of the reserve.

The site was designated in the 1970s, but subsequently the focus of the UNESCO programme shifted from the idea of isolated natural environments to one that allows for the interaction with man in terms of sustainable living and education.