Teesmouth National Nature Reserve - "Main habitat: sand dunes, grazing marsh, intertidal sand and mudflats" "The reserve is split into 2 main sections. North Gare is an area of dunes and grazing marsh, the domain of lapwings and flocks of curlew. Seal Sands is one of the largest areas of intertidal mudflats on England’s north-east coast. When the tide is out, hundreds of waders, including redshank and dunlin peck through the mud." "The colony of harbour seals haul out on the sand banks at low tide; their pups are born here each summer, making Seal Sands the only regular breeding colony of these animals on England’s north-east coast."
- from the Natural England website - Download the site leaflet (it states "An easy-access footpath connects the Cowpen Marsh car park with two wheelchair accessible hides overlooking Seal Sands, and with the Greatham Creek Seal Viewpoint."