Marking his final day in office, Mr Ahern was joined by the Northern Ireland First Minister Ian Paisley to officially open the Battle of the Boyne site.

The leaders used 17th-century swords to cut the ribbon on the new €15m centre, which opens to the public today.

Mr Ahern said he hoped people would travel from all over the island to visit the centre and to "develop the greater mutual understanding essential to peace and reconciliation".

He added: "We need -- all of us -- to understand our shared history if we are to build a shared future.

"The principles and ideals that we hold dear are the same -- liberty and equality, democracy and peace. If we hold fast to these shared ideals, our children will have an inheritance to treasure."

Mr Ahern said in recent years many from the nationalist tradition have come to a greater appreciation of the history, traditions and identity of those from the unionist tradition.

"We have come to understand the pride you take in your history and to recognise that your history is our history too," he said.

Mr Ahern said it's not history that is of concern now, but the future. "In the future, let us respect each other and our identities. Let us be reconciled with each other, and let us be friends, and let us live in peace," he said.

Directing his comments directly at people from the Protestant, unionist and loyalist tradition, who had travelled to the site, Mr Ahern said it was an honour to have them there.

"For far too long, many people from Northern Ireland feared to travel to the south. I am glad to say those days are over," he said.

Mr Paisley said he started something a year ago when he met Mr Ahern at the same site, and he wanted to see it complete.

"It was nice to know that one of the last acts we did when we were in office, he as Taoiseach and me as First Minister, is we met at the Boyne and cut the tape," he said.

And he was in no doubt of the importance of the event and its symbolism in terms of North-South relations.

"To the bad old days there can be no turning back," he said.

"The killing times must be ended forever, and no tolerance must be given to any who advocate their return. A strong dedication to peace and an intolerance of murder must drive us forward. The coming generation has a right to demand this, and we cannot fail them," he added.

Mr Paisley said his relationship with Mr Ahern was extremely positive.

"There are many things that we disagree about but there are many things we agree about. We agree that we both are entitled to live here and we want to make it the best possible place for all religions and all people," he said.

The 82-year-old Mr Paisley is due to resign over the next month as leader of the Democratic Unionist Party and will be replaced by Peter Robinson.

The centrepiece of the Battle of the Boyne centre is Oldbridge House, a 17th-century mansion.

The heritage centre commemorates the battle in 1690 between King William of Orange and his father-in-law King James II.