'Mind-blowing' ancient bones discovery sparked by family holiday

To play this video you need to enable JavaScript in your browser. This video can not be played Figure caption, The "once in a lifetime" discovery could rewrite history, researchers say By Greg Davies  and  Tink Llewellyn , BBC Wales Published 16 July 2026 Updated 1 hour ago A family holiday sparked a series of "remarkable" archaeological discoveries which one expert says could change what is currently known about Britain's prehistory. John Bolton, an archaeologist, was visiting the 11th Century Pembroke Castle in 2010 when he heard there was a cave beneath it. His interest grew when he discovered that the cave, known as Wogan Cavern, showed little signs of previous excavation - so he "badgered" Dr Rob Dinnis, from the University of Aberdeen, to take a look. Small digs have since uncovered "extremely rare" evidence of early humans and animals - including the bones of a hippopotamus which roamed Wales 120,000 years ago. The University of Aberdeen will now lead a larger five-year exploration of the site, which archaeologists hope could reveal "a great deal about our early prehistoric forebears". Image source, John Bolton Image caption, John Bolton now works on the archaeological excavation at the site "It was by accident, really," said Bolton, who described the cave as "huge" and "unlike any other" he had seen in the UK in terms of its archaeological potential. "[I] saw the castle, and then heard that there was a cave under it, so that automatically piqued my interest. "I noticed, very low down, there was an old calcite floor. So it suggested that, if anything had been removed in the past, it was very little." Bolton then visited Tenby museum and noticed that there was a small collection of stone tools from the cave. "I thought, if that's here, [then] the Paleolithic - which we're very interested in - might be deeper. "I badgered Rob for many, many years. A few years later, he relented, and we found the time to come down and have a little look." Image caption, Rare evidence for early Homospaiens and even Neanderthals has been found in the cavern Wogan Cavern was thought to have been dug out by the Victorians, and it was long assumed that there was little archaeological material left at the site. But small excavations between 2021 and 2024 , brought on by Bolton's chance visit to the cavern, uncovered evidence of both humans and animals over more than 120,000 years. Dinnis, who directed the initial digs and will lead the new excavation project , said many caves were "emptied out" during the 1800s, and so "to find one where we have quite a lot still in place, not excavated out, is completely unique". "All of that information or most of that information [from sites excavated in the Victorian era] has been lost," Dinnis added. Image caption, Pembroke Castle, the birthplace of Henry Tudor, is a popular tourist attraction Image source, University of Aberdeen Image caption, Tiny bones (microfauna) found at the site and pottery from human habitation Dr J