Mare Fen Local Nature Reserve

Provided by:
Cambridgeshire County Council

This 17 hectare site is a large expanse of permanent pasture lying in the floodplain of the River Great Ouse used for summer grazing for cattle or sheep.

Grassland like this was once common in the Ouse Valley, but the reserve is now one of the remaining precious fragments. The wet meadows contain a mosaic of grassland types complemented by reed fringed ditches and ponds.

The water levels are controlled using sluices and overflows. During the winter the sluices are open to allow the fen to flood and closed late spring for grazing.

Habitat type

Wet grassland meadow, ditches.

Grid Reference

TL 366 698

Conservation Status

  • Local Nature Reserve
  • County Wildlife Site


When flooded in winter, this reserve is excellent for birds, providing much needed shallow water for over-wintering waterfowl and wading birds.

Mare Fen is a great place to see wildfowl such as mute swan, wigeon, teal, shoveler, tufted duck and snipe.

During the spring and summer a range of aquatic plants flourish. Dragonflies, frogs, toads, newts and grass snakes can be found around the ponds and ditches. Badgers are known to take advantage of the soft ground to forage for worms and muntjac can be seen grazing.

Facilities and equipment

Access to the site is gained from Station Road between the villages of Swavesey and Over.

The nearest parking can be found at the north end of Swavesey village (Church End). The reserve is on the left hand side, past the old level crossing. Enter the reserve over a stile next to an interpretative panel on High Causeway Bridge.

  • Age range: 1 - 99
  • Type: Local Authority Service

Last updated on: 19/08/2020

Report incorrect information

Tags and groupings:
Logo of Cambridgeshire County Council

Contact details


Swavesey CB24 4QJ

View Google map