A CAUSEWAY man is facing a possible five-year jail term after he was prosecuted for demolishing an ancient ring fort on land belonging to his family.

In the first case of its kind to be heard in an Irish Court, John O'mahony with an address at Clashmealcon, Causeway appeared at Tralee Circuit Criminal Court last where he pleaded guilty to carrying out unauthorised work near a monument on his family's farmland in Causeway in 2008.

The court heard that the family of Mr O'mahony, a 64-year-old farmer, owned lands which contained a ring fort and a series of underground tunnels, or souterrains, which dated back to between 500 and 100AD.

The ring fort and souterrain system were deemed to be national monuments of historic importance and had been placed on a national register.

While landowners are allowed carry out works on or near national monuments that are on the register they must contact the Department Environment and receive express written permission from the minister before they proceed.

Judge Carroll Moran was told that in February 2008, without seeking permission from the department, John O'mahony hired workers who demolished the majority of the ring fort and used the materials to fill in a nearby pond which Mr O'mahony believed posed a safety risk to children and livestock.

In the course of the work, the majority of the fort was destroyed while two thirds of the souterrian was demolished.

When the Department of the Environment learned of the demolition they contacted Gardaí in Listowel who launched and investigation.

During the garda investigation, John O'mahony initially claimed he was unaware that the site had any great historical significance.

However it emerged that Mr O'mahony had previously objected to a planning application seeking permssion to construct four houses on the same site on the grounds that it contained a "historical ring fort".

He subsequently admitted to ordering the demolition of the fort but said he didn't know he wasn't allowed touch the site without two months notice and permission from the minister.

Prosecution Barrister told the court that as a result of Mr O'mahony's actions "part of the history and culture of county Kerry has been irretrievably lost."

Defence Barrister Mr John O'sullivan said his client simply didn't understand the implications of his actions.

"He did a silly thing for what he thought were the right reasons. He's brought a lot of trouble on himself for really very little gain," said Mr O'sullivan.

Judge Carroll said that due to the unusual nature of the case he would need time to reflect before passing sentence. He adjourned the case until January 16 2012.