Dairy farming could have been happening in Wales as early as 3,100BC, according to new research.
Shards of decorated pottery taken from the Trellyffaint Neolithic monument near Newport, Pembrokeshire, were found to contain dairy fat residue.
The residue could only originate from milk-based substances such as butter, cheese, or more probably yoghurt.
George Nash, of the Welsh Rock Art Organisation, said it was the earliest proof of dairy farming in Wales.