Fact Five: Isotope analysis has proved that the Penywyrlod long cairn has a 5,700 year old human tooth buried under it

The article in the American Journal of Physical Anthropology in July 2017 provided the isotope analysis of enamel from a tooth under the Penywyrlod long cairn that they dated with 70 year accuracy to between 5,770 and 5,630 years ago. So indisputably early Neolithic.

If that was found just 26 miles away, why not under Garn Goch’s similar long cairn? They’ve done such excavations in England and at Penywyrlod, so why not at Garn Goch?

But then that doesn’t prove the surrounding stones were Neolithic. They could be Iron Age walls that happened to be built around a Neolithic cairn, but some surprising numbers make that highly unlikely. See Fact Six.