A new find on a map could lead a Kilwinning group to features that are more than 4,000 years old.

Jeni Park of Kilwinning Heritage has always had a passion for old maps, so when browsing aerial photos in the National Library of Scotland’s online resources, she discovered what she thought was an ancient feature that nobody had noticed before.

The photograph from 1950 showed two large concentric circles at Blair Ardoch farm near Kilwinning, and were unlikely to be a natural feature.

Jeni said: “I was surfing the NLS website and was looking at the air photos. When I saw the two large ring marks in the empty field, I had a “could it be” moment.

"I checked and couldn’t find any previous historical or technical reference to these marks, so I realised I had possibly stumbled on an unknown and unrecorded ancient site.”

She shared her findings with Kilwinning Heritage colleague Dr Ralph Shuttleworth, who agreed the marks looked man made, identifying them as parch marks caused by very small differences in the amount of moisture retained in the soil.

Consultation with Kilwinning-based Rathmell Archaeology backed up their interpretations, and onsite measurements revealed the circular feature was about 60 metres in diameter.

The only way to be sure about the marks was to dig, and the first phase of investigation by Ralph, Jeni, and a very small team has now been completed.

Their digging and scraping has revealed two shallow ditches about two metres wide and a substantial stone-lined hole for a timber post or stone upright of some kind within the inner ditch.

Dr Shuttleworth, veteran of many archaeological digs all over the UK, says: “A feature with this form and size is called technically a henge, Neolithic or Bronze Age in date, so somewhere between 4000 and 6000 years old.

“Henges can contain ritual structures such as stone or timber circles, in our case probably timber, and could have been used for worship or to honour the ancestors in some way.

“It appears that nobody has been aware of this site until Jeni spotted it by chance.

“What we’ve discovered is new knowledge and is a first for Kilwinning Heritage. These are only the results of the first investigation and it is far too early to come to any definite conclusion, but we have considered some possibilities in order to guide further work.”