Anti-Incineration protesters plan to gather at Newgrange, in Co Meath, this morning, the winter solstice.
They aim to highlight the proximity of the world-famous burial chamber to the site proposed for a waste-management facility, including an incinerator for municipal waste, at Carranstown, about four miles away.
A silent protest has been organised for the perimeter of the monument by the Battle for the Boyne Forum, a cross-Border group that appealed the decision of Meath County Council to grant permission for the facility to Indaver Ireland.
Dúchas, the heritage service, was accused of failing to protect the Boyne Valley, a UNESCO-recognised world heritage site, because it did not object to An Bord Pleanála.
The rays of the rising sun illuminate the burial chamber that forms the focal point of the 5,000-year- old monument on the shortest day of the year.
"The proposed site of the incinerator is close to the World Heritage site of Newgrange and Brú na Bóinne and right on the 'footprint' of the historic Battle of the Boyne," Mr Brian Hanratty, of the forum, said. The management plan for Brú na Bóinne, recently published by Dúchas, "is of little value if it not supported with key actions to protect this area of enormous archaeological importance," he added.
Among those who objected to the granting of planning permission were the former Taoiseach, Mr John Bruton; the former Attorney General, Mr John Rogers; and the No Incineration Alliance, an umbrella group for a large number of individual and group objections.
If An Bord Pleanála decides to grant permission "it would be an act of cultural vandalism on a scale never before seen in Ireland, and they have called on political, heritage, environmental and community groups throughout Ireland to express their outrage at such a prospect," Mr Hanratty said.
The group also criticised what it termed the absorption of Dúchas into the Department of the Environment, saying it was a bad omen for the protection of sites of archaeological and historical importance, such as Carrickmines Castle.
An Bord Pleanála held a four-day oral hearing into objections to the planning permission for the Indaver facility earlier this year and a decision is expected in the next 10 weeks.