Specialist radar equipment is being used to determine if there is a passage tomb located at the site of Millmount Fort in Drogheda, Co Louth.
The Millmount Archaeological Remote Sensing project is seeking to find out more about the Norman period at the site.
The initial fieldwork took place at the end of last week and finished yesterday, where ground penetrating radar was used to non-invasively look below the surface.
Other techniques will also be used at the site.
Archaeologist Dr Conor Brady of Dundalk IT, who is involved in the project, said there is folklore and mythology associated with the mound, which is reputed to be the burial place of Amhairgin, a mythological figure who invented song and poetry.
Speaking on RTÉ's News At One, Dr Brady said that while there may not be any dramatic announcements in the near future, the first steps have been taken.
"Perhaps we have data now that we'll be able to explore the complex history of the site dating right the way back, possibly to pre-historic times."
Researchers will get a first glimpse at the data collected in the next few weeks and the project will be completed by next summer.
Millmount Fort is a historic monument that is believed to have been founded by Hugh de Lacy in the 12th Century.
The site is a short distance from the world-famous Newgrange archaeological site.
