Castlemartin Corse is an extensive wetland whose management is linked to the nearby National Trust Gupton Farm (NPRN 22024). The site has an area of 30.4 hectares (75 acres) and is managed by Natural Resources Wales as a Site of Special Scientific Interest. This site is designated due to its biological qualities.
The site is the best example of a calcareous fen in Pembrokeshire. The 20 hectare reed-bed is also the largest and most diverse in the county.

The landscape is under study for the EU-funded CHERISH Project. Survey for the CHERISH Project. ? Crown: CHERISH PROJECT 2017. Produced with EU funds through the Ireland Wales Co-operation Programme 2014-2020. All material made freely available through the Open Government Licence.

T. Driver, 1 May 2018