Volunteers are helping archaeologists search for signs of a medieval castle thought to be under a village car park.
A similar dig took place at Angle Bay in Pembrokeshire last year
Researchers believe the castle once stood at the site in Maenclochog at the foot of Pembrokeshire's Preseli Hills.
Villagers are working with professional archaeologists for two weeks in a bid to find out more about the land.
A topographical survey of the site last year suggested the site was probably that of the castle and possibly an earlier Iron Age fortification.
Documentary evidence suggests there was a castle at Maenclochog dating back to the 13th Century.
The dig, involving part of the village carpark, has been organised by local enterprise organisation Planed, with the help of Cambria Archaeology and Pembrokeshire National Park.
Planed's Christian Donovan said research was commissioned last year to come up with possible locations.
"They had always thought there was a castle in Maenclochog and people living there wanted to find out more about it," she said.
Around 20 amateurs will take part in the dig which started on Wednesday and at the end of each day villagers will be invited to tour the site for an update on what - if anything - has been found.
"We also have local school children coming to have a look next week," added Ms Donovan.
A similar project last year saw volunteers uncover human remains as they searched for a pre-Norman cemetery at Angle Bay in Pembrokeshire.
"They found a body last year - we don't think that will happen this year," added Mrs Donovan
She said the aim of the projects was to interest people in the history of their communities and get them actively involved in researching their heritage.