Beneath the thick limestone walls of Pembroke Castle, down a narrow passage cut through the foundations of a 12th-century fortress, a natural cavern opens into darkness. Wogan Cavern has been known to locals and castle visitors for generations, but what researchers have found inside its undisturbed sediment layers is now drawing attention from some of Britain’s leading prehistorians. As of spring 2025, excavation teams and laboratory scientists have confirmed stratified deposits spanning thousands of years, evidence of Mesolithic hunter-gatherers dating to roughly 11,000 years ago, deeper Palaeolithic layers whose age has not yet been pinned down, and, critically, surviving ancient DNA in bones and sediments that could eventually identify which species of human sheltered here.
What the excavations have confirmed
Wogan Cavern sits directly under Pembroke Castle on the tidal Pembroke River in southwest Wales. The cave is large enough to walk through, and its mouth once opened toward the estuary before medieval builders enclosed it within the castle’s defenses. That enclosure turns out to have been a gift to science: the construction appears to have sealed the cave’s floor deposits, preserving a stratigraphic sequence that centuries of farming and coastal erosion have destroyed at comparable sites across Britain.
The clearest occupation phase belongs to Mesolithic hunter-gatherers who used the cave around 11,000 years ago, during the centuries when Britain was still connected to continental Europe by a land bridge. Animal bones, stone tools, and charcoal from that period have been recovered in readable layers, giving archaeologists a snapshot of life on the western edge of a rapidly warming post-glacial landscape.
Below the Mesolithic deposits, excavators have identified older Palaeolithic layers. These deeper finds have not yet been dated or described in a peer-reviewed publication, so their precise age remains unknown. Whether they belong to the Upper Palaeolithic (roughly 40,000 to 10,000 years ago) or stretch further back is one of the central questions driving ongoing research.
A parallel breakthrough came from the laboratory. A PhD project supported by the Natural History Museum in London confirmed that ancient DNA survives in both bone samples and cave sediments from the site. That opens the possibility of environmental DNA (eDNA) analysis, a technique that can detect the genetic traces of animals, plants, and hominins even when no visible fossils are present. If preservation extends into the Palaeolithic layers, eDNA could reveal not just which creatures lived near the cave but which human species carried their kills inside it.
The Neanderthal question
Much of the public excitement around Wogan Cavern centers on whether Neanderthals once used the site. Neanderthals are known to have occupied parts of Britain before roughly 40,000 years ago, and caves across southern England and Wales, including Paviland Cave on the Gower Peninsula about 50 miles to the east, have produced evidence of their presence. A confirmed Neanderthal layer at Wogan Cavern would extend the known range of Neanderthal activity along the Welsh coast and could shed light on how they responded to the advancing ice sheets that eventually made much of Britain uninhabitable.
But that confirmation does not yet exist. Media coverage has referenced possible Neanderthal evidence, and the undated Palaeolithic layers are consistent with a timeframe when Neanderthals were present in the region. However, no diagnostic stone tools of Neanderthal type have been formally published from the site, and no ancient DNA results have yet identified Neanderthal genetic material in the sediments. For now, the Neanderthal connection is a working hypothesis rather than an established finding.
Why the stratigraphy matters so much
Britain has no shortage of Palaeolithic cave sites, but most of them come with serious complications. At Kent’s Cavern in Devon, early excavations in the 19th century mixed layers and lost context. At Creswell Crags on the Nottinghamshire-Derbyshire border, some deposits were disturbed by quarrying. Even Paviland Cave, which produced the famous “Red Lady” burial (actually a young man stained with red ochre and dating to around 33,000 years ago), has a complex excavation history that makes reinterpretation difficult.
Wogan Cavern’s advantage is that its layers appear to be intact and stacked in chronological order. If that holds true across the full depth of the deposits, researchers could track changes in climate, animal populations, and human behavior across a continuous timeline, something few British cave sites can offer. Combined with ancient DNA, the sequence could show, for example, when certain prey species disappeared as glaciers advanced, or when a shift in stone-tool technology signals the arrival of a new group of people.
That combination of clean stratigraphy and molecular evidence is what has drawn institutional backing. The Natural History Museum’s involvement signals that the site meets a high threshold for scientific potential. Zooarchaeologist Louise Martin of University College London has been linked to analysis of the animal bone assemblages, and the excavation itself has involved specialists from multiple institutions working under controlled conditions designed to prevent contamination of DNA-bearing sediments.
What still needs to happen
The gap between what Wogan Cavern promises and what it has delivered so far is real, and researchers are candid about it. Several milestones remain before the cave’s place in British prehistory can be fixed with confidence:
Firm dates for the Palaeolithic layers. Radiocarbon dating works reliably back to about 50,000 years. For older deposits, techniques such as optically stimulated luminescence (OSL) or uranium-series dating would be needed. Until dates are published, the age of the deeper occupation phases is an open question.
Full-scale ancient DNA sequencing. The pilot work confirmed preservation, but extracting and sequencing eDNA across multiple layers is technically demanding. Contamination from modern visitors, groundwater movement, and chemical degradation of ancient molecules all pose risks. Results from the ongoing PhD project are expected in the coming years but have not yet been released as of May 2026.
Detailed artifact analysis. Stone tools from the Palaeolithic layers need to be classified by type and manufacturing technique. Tool typology can indicate which cultural tradition, and by extension which hominin species, produced them. That analysis has not yet appeared in published form.
A full geoarchaeological survey. While the stratigraphy appears undisturbed, no published assessment has mapped the full extent of the deposits or evaluated whether any sections were affected by the castle’s construction, later modifications, or natural water action.
A castle, a cave, and the long view
Pembroke Castle already draws tens of thousands of visitors each year. It was the birthplace of Henry VII, the founder of the Tudor dynasty, and its massive round keep dominates the town. Wogan Cavern is accessible through a gate in the castle’s lower levels, and visitors can peer into the gloom where the cave meets the tidal waters of the estuary. For most, it has been a curiosity, a footnote to the medieval tour.
That is changing. As the scientific significance of the cave becomes clearer, heritage bodies including Cadw, the Welsh government’s historic environment service, will face decisions about balancing research access, conservation, and public engagement. Foot traffic and fluctuating humidity can damage fragile sediments and degrade organic material. At the same time, the story of Ice Age hunters sheltering beneath what would become a Norman fortress is exactly the kind of layered narrative that connects people to deep time in ways that abstract dates and species names rarely do.
For now, the most honest summary is this: Wogan Cavern has already proved that Mesolithic people lived beneath what is now Pembroke Castle roughly 11,000 years ago, and that ancient DNA survives in its deposits. It has shown that older, potentially far older, occupation layers exist below. Whether those layers record the presence of Neanderthals, or document the moment when modern humans first pushed into western Britain, is a question the evidence cannot yet answer. The work to answer it is under way, and the cave, sealed in darkness beneath eight centuries of stone, is not going anywhere.
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*This article was researched with the help of AI, with human editors creating the final content.
