NATIONAL NATURE RESERVE
Merthyr Mawr Warren
Origins
A Remnant of Europe’s Greatest Dune System
Merthyr Mawr Warren is more than a nature reserve; it is a living, shifting narrative written by the wind and the sea over thousands of years. The landscape we see today is a beautiful remnant of what was once an expansive wilderness stretching from the Ogmore estuary all the way to the Gower peninsula.
These dunes began their slow, breathing journey during the late Neolithic era. By the 13th and 14th centuries, catastrophic winter storms drove vast waves of sand inland over the limestone cliffs, sculpting a dramatic sanctuary rising 200 feet above the shore, crowned by the legendary ‘Big Dipper’—Europe’s second highest sand dune.
200 ft
Big Dipper height
Heritage
An Unbroken Human Narrative
Though the shifting sands constantly reshape the topography, they also act as a silent guardian of our shared past. Beneath these sweeping hills lies an unbroken thread of human life, holding the secrets of late Neolithic hearths, Bronze Age burial mounds, Iron Age settlements, and Roman outposts.
To walk the paths of the Warren is to tread where thousands of generations have lived, worked, and rested. Because of this exceptional archaeological density, a significant portion of the Reserve is designated as a Scheduled Ancient Monument, protected with the utmost reverence so its stories can continue to whisper to those who visit.
A quarter of all Welsh flora species can be found within these 840 acres.
National Nature Reserve · SSSI · SAC
Stewardship
Caring for a Shifting Sanctuary
As custodians, our work is a delicate dance with nature. Over the last century, the Warren has undergone a dramatic transformation. What was once a vast expanse of wild, mobile sand dunes has gradually stabilised and vegetated.
In medieval times, this was managed as an active, productive warren with a dedicated full-time keeper. A thriving rabbit population naturally grazed the grasses, keeping the open sands active and dynamic. Following the devastating myxomatosis outbreaks of the 1950s, rabbit numbers fell, and vegetation claimed much of the open dune landscape.
Today, we work gently to guide the reserve back to a healthy equilibrium. Our conservation efforts focus on restoring active sand movement nearest the shore, ensuring rare insects and pioneer flora have a place to thrive.
By grazing our pastures with traditional cattle, using selective mechanical mowing, and supporting the natural recovery of rabbit populations, we maintain a rich mosaic of habitats. The result is a vibrant haven where wild orchids, mosses, and butterflies flourish, offering visitors a timeless connection to the wild.
Wildlife & Habitats
Four Distinct Habitats in 840 Acres
Mobile Sand Dunes
Dynamic open dune faces supporting rare invertebrates and pioneer plants found nowhere else in Wales.
Dune Slacks
Damp hollows between dunes — a refuge for marsh helleborine, fen orchids, and rare wetland invertebrates.
Limestone Grassland
Thin soils over ancient limestone support a carpet of wildflowers, attracting rare butterflies and bees.
Seasonal Lakes
A rare karstic system of spring-fed seasonal lakes — one of the most unusual freshwater habitats in Wales.
Cooperation
Protecting the Reserve Together
To safeguard the fragile biodiversity and maintain this peaceful sanctuary for all, we kindly request that visitors register for permits when participating in specific activities. By planning ahead, you help us ensure that unassuming wild flowers, ground-nesting birds, and rare habitats remain undisturbed.
Horse Riding Permits
To safeguard our sensitive flora and ensure a safe environment, horse riders require a seasonal or day permit. Kindly arrange yours online before visiting.
Professional Dog Walkers
We welcome professional dog walkers who share our commitment to wildlife protection. Licences are issued to ensure grazing livestock and rare ground-nesting birds are not disturbed.
Commercial & Filming Events
The untouched landscape of the Warren provides a dramatic natural canvas. If you wish to host a commercial event, photoshoot, or broadcast filming, please get in touch to discuss consent.
Or call 01656 662413
Stay Connected
Get Involved
Visit our Facebook page to find volunteer opportunities and updates on Reserve activities.
Visitor Information
Accessing the Sanctuary
The main entrance to this peaceful valley is the Candleston Car Park. A gentle reminder that an ANPR system is in operation. The parking fees collected are put directly back into the estate’s conservation fund, supporting our rare maternity bat roosts and SSSI dunes. Season tickets and toilet facilities are available on-site.