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Explore the Blue Lagoon at Abereiddi

A view from a cliff top looking down towards a rocky cove which almost completely encircles a blue-green lagoon known as the Blue Lagoon at Abereiddi, with the sea stretching out towards the horizon beyond.
The Blue Lagoon at Abereiddi, on the Pembrokeshire Coastal Path | © NTPL/David Sellman

Abereiddi’s Blue Lagoon in Pembrokeshire is surrounded by rugged rocks and some remaining ruins still hint at the area’s industrial past. Popular in the summer months for coasteering and kayaking, walkers can enjoy the rugged coastline and clifftop views too. Discover the beauty of this part of Pembrokeshire and how we are working to adapt to the forces of nature.

Blue Lagoon closed from 21 September to 2 November 2024

The Blue Lagoon will close to protect breeding seals from Saturday 21 September - Saturday 2 November 2024. Please note we may also close access to Traeth Llyfn, and these dates may be subject to change depending on the behaviour of the seal population. Visitors will still be able to watch these wild creatures in their habitat from the Wales Coast Path. To avoid disturbing seals at this very important time of year, we recommend following the Marine Code: Stay quiet, keep your distance and at least 50m away from seals and never come between a seal and her pup, or a seal and the sea and don’t take dogs near a seal breeding area.

An industrial past at Abereiddi

The Lagoon just to the north of the beach, was formerly the main slate quarry of the St Brides Slate Company and was active up until 1910. The slate gives a brilliant aqua blue colour to the water. It’s a popular spot for coasteering and climbing along the cliffs at sea level.

A former slate quarry

Pembrokeshire played a lead role in the slate industry, with around 100 quarries in the county in the late 18th century. Slate that was extracted from Abereiddi was transported by tramway to the neighbouring Porthgain Harbour and shipped out. The Blue Lagoon was formed when the channel connecting the quarry to the sea was blasted, allowing the sea to flood in.

Ruined quarry buildings still sit on the clifftop, with the remains of the workmen’s cottages adjacent to the car park, along what was called The Row or The Street. You’ll also spot the foreman’s house and the powder store here.

Coastal change at Abereiddi

Coastal change is inevitable, and the forces of nature are part of the beauty and appeal of the coast. Here at Abereiddi, Pembrokeshire we are working with others to adapt to natural processes.

There are few places in Pembrokeshire that feel the power of the sea more than Abereiddi. Since the deteriorating sea wall was removed in 2012, the pace of change has sped up dramatically. During the winter storms of 2014 there were overnight land losses of more than five metres.

Coastal erosion and historic remains

The beach is realigning itself most rapidly at the National Trust owned north end, as modelled by a study that the Trust helped commission with Pembrokeshire County Council.

The erosion is also resulting in the partial loss of the quarry worker cottages. As hard sea defences at this location are not sustainable, following electronic surveying by an archaeologist, we carefully dismantled the seaward end of the storm-damaged cottages with help from local Prince's Trust volunteers. The stone was stored and made available for other local conservation projects.

A view from a cliff top looking down towards a rocky cove which almost completely encircles a blue-green lagoon known as the Blue Lagoon at Abereiddi, with the sea stretching out towards the horizon beyond.

Discover more from Abereiddi to Abermawr

Find out how to get from Abereiddi to Abermawr, where to park, the things to see and do and more.

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