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Cwm Ivy on the North Gower coast

A view of the Cwm Ivy Marsh, Whiteford Burrows, Swansea. There's white-tinged marshy terrain with some trees in the foreground, while a forest high up on a hillside is visible beyond.
Cwm Ivy Marsh, Whiteford Burrows | © National Trust Images/James Dobson

Cwm Ivy marsh is a small parcel of land on the coast of North Gower. It was claimed from the sea to be used as farmland in the 17th century and was protected by a sea defence which over the years increased in size and strength. In 2014 the sea wall breached, and the sea reclaimed the land, transforming Cwm Ivy freshwater marsh to salt marsh.

Shifting Shores at Cwm Ivy

Our 2015 Shifting Shores report held one clear message, as a nation we can no longer build our way out of trouble on the coast. This means at sites such as Cwm Ivy we no longer try to defy nature by holding back the tide, instead we let nature take its course.

Sea wall breach

In November 2013, Cwm Ivy sea wall was showing signs of distress. Repeated heavy rain had welled the inland stream to unprecedented levels and the sluice gate designed to drain the marsh simply wasn’t able to remove the water fast enough.

The pressure of water forced a small hole under the wall and the following winter of storms, rain, high tides and storm surges began to widen the hole and allow significant amount of sea water into the freshwater marsh.

By August 2014 the summer storms finally caused the wall to fail, effectively ending its time as a sea defence.

Looking forward

Almost as soon as the breach occurred the vegetation underwent a radical change. The farmland grasses died back within days and the trees rapidly began dropping leaves and most were standing dead wood by spring 2015.

Was this a problem? Visually this was not an improvement over the lush greens we used to see, however this transition phase, unsightly as it was, was temporary until the salt marsh plants started to take over.

Thrift flowering on the cliff tops at sunset at Pentire
Thrift flowering on the cliff tops | © National Trust Images/Ross Hodd

Salt marsh returns

Fast forward to March 2015 and the first signs of life from salt marsh plants could be seen; delicate scurvey grass, Salicorina (samphire) species, sea blight, thrift and sea spurrey. By June 2015 the whole marsh was alive with the vibrant greens of a healthy salt marsh.

Landscape transformed

Three years on from the breach Cwm Ivy marsh has transformed from grazing pasture and by the winter of 2017, we had a fully functioning wildlife-rich tidal salt marsh.

Birds to see at Cwm Ivy

The tidal nature of Cwm Ivy marsh brings in a host of fresh nutrients, fish and invertebrates with it, providing a veritable feast for a range of bills. Look out for:


The bright white plumage of little egrets makes them the most noticeable species. They can be spotted daily, often bent over a shallow pool, patiently looking for fish trapped by the receding tide, along with their larger cousin, the grey heron.


If you’re lucky you may even see the dazzling flash of electric blue as kingfishers dive in for prey. They prefer slow moving water where they hunt for fish and aquatic insects.


They can be seen here throughout the year, listen out for their distinctive ‘peewit’ sounding calls. They also breed here in small numbers and lay their eggs on the ground around the outskirts of the marsh.

Bird watching

There are two bird hides - Cheriton hide and Monterey hide, located either side of the marsh and perfect for enjoying the sights and sounds of this evolving marsh, which also forms part of the wider Whiteford National Nature Reserve.

A view of the Cwm Ivy Marsh, Whiteford Burrows, Swansea. There's white-tinged marshy terrain with some trees in the foreground, while a forest high up on a hillside is visible beyond.

Discover more at Whiteford and North Gower

Find out how to get to Whiteford and North Gower, where to park, the things to see and do and more.

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