Get closer to nature at Cors Geirch in Llŷn

Cors Geirch, Llŷn Peninsula

Explore a wetland of international importance. Cors Geirch is recognised as a Site of Special Scientific Interest and a special area of conservation.

Enjoy a walk at this beautiful reserve and get closer to nature. This special place is the best outdoor classroom ever, a rich haven for wildlife, providing the habitat for nationally rare plants and invertebrates.

Wildlife haven

Discover a complex wetland reserve, home to numerous nationally rare plants and species, such as the small red and blue-tailed damselflies and the marsh fritillary butterfly. The marsh is also the only locality in Wales known to support Desmoulin’s whorl snail.

The wetland is thought to occupy the site of a large pro-glacial lake. Springs rise in the ridges on either side, carrying dissolved minerals into the bog that contribute to its rich nature.

Alkaline fen

Much of the interest in the Cors Geirch area is the environmental significance of the alkaline fen and its vegetation. The rich fen is rare in the UK and the alkaline water draining into the basin from porous limestone rocks results in an unusual and rare combination of plants, including:

  • narrow-leaved marsh orchid
  • black bog rush
  • marsh fern
  • bog myrtle
  • purple moor grass
  • blunt-flowered rush
  • common reed
  • great fen sedge
  • slender cotton grass

Because this type of threatened wetland is so rare, and because of the incredible range of wildlife to which it plays host, the reserve has a number of designations at hand to protect it.

Something to see in all seasons

In spring, the woodland on the slopes above the bog is transformed by a spectacular cover of primroses, wood anemone and bluebells. There’s something special for you to see year round.

Cors Geirch is owned and managed by Natural Resources Wales (NRW).