A diverse reserve nestling in the Mimram Valley, where a fantastic two storey hide gives great views of the wildlife in clear, chalk stream waters.

A diverse reserve lying in the Mimram Valley which contains a variety of habitats including wet meadow, tall fen and swamp, alder carr, willow scrub, willow pollards and chalk stream. The tall fen/swamp occurs around a lagoon and along adjacent channels, and has a mixture of common reed, reed sweet-grass and common reed-mace. Water voles can be seen swimming in the reedbed channels. The surrounding banks support great horsetail, butterbur and town hall clock. Greater tussock sedge grows here, a species now uncommon in Hertfordshire.


If you are interested in volunteering at this site please click here to see if there are any volunteering opportunities coming up in the future. 

Species and habitats

Siskin, Water Vole, Yellowhammer, Weasel, Pied Wagtail, Reed Bunting, Kingfisher

Nearby nature reserves

Tewin Orchard and Hopkyns Wood
1 miles - Herts and Middlesex Wildlife Trust
Lemsford Springs
3 miles - Herts and Middlesex Wildlife Trust
Stanborough Reedmarsh
3 miles - Herts and Middlesex Wildlife Trust

Nature reserve map

Reserve information

Between Welwyn Garden City and Hertford, along the driveway to Tewin Bury Farm Hotel
Map reference
TL 265 140
Great for...
Best time to visit
Apr - Jul
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Opening Times
Open at all times
3.60 hectares

Open at all times. Lower storey of hide is wheelchair friendly.
Please park in the first car park on the right of the drive to Tewin Bury Farm Hotel. If necessary open the gates and close them behind you.
Dogs allowed
Grazing animals
Longhorn cattle graze the meadow adjacent to the car park from time to time; also managed by the Trust
Reserve manager
Herts & Middlesex Wildlife Trust
Tel: 01727 858901