This marsh and fen on shallow peat is formed by seepage from the boundary between clay and limestone. Plants in wet areas include blunt-flowered rush, marsh pennywort, wild angelica and Menyanthes trifoliata, a rare species of bogbean. Drier areas have grasses and herbs which attract butterflies and dragonflies. The site includes a stretch of Harpers Brook.[3]
The site is private land with no public access, but the Nene Way runs along its eastern boundary.
^"Map of Aldwincle Marsh". Sites of Special Scientific Interest. Natural England. Retrieved 19 February 2017.
^"Aldwincle Marsh citation"(PDF). Sites of Special Scientific Interest. Natural England. Archived from the original(PDF) on 20 December 2016. Retrieved 19 February 2017.