A report on the former Maze Prison site has revealed how consultants saw the retention of a H-Block hospital where IRA hunger strikers died as key to the success of the overall project.
Ulster Unionist leader Mike Nesbitt chose the first day of the Balmoral Show, which is now held on the Maze site, to reveal the previously unseen documents.
They had been kept under wraps while a lengthy battle was fought after a Freedom of Information request by the UUP.
Plans to redevelop the former prison site have stalled because of the Maze's long association with the Troubles, particularly the hunger strikes.
First Minister Peter Robinson angered Sinn Fein last year by vetoing the Maze Peace Building and Conflict Resolution Centre, and £18 million in EU peace funding earmarked for the project had to be redistributed.
The DUP has always insisted that, even if it were built, a peace centre would be separate from the old prison buildings to ensure that the entire site didn't become a "shrine to terrorism".
However, the August 2011 business plan by commercial real estate company Colliers International, contained in three documents, controversially recommended keeping H Block 6, including the prison hospital where the 1981 hunger strikers led by Bobby Sands died.
This was seen as central to marketing the development and setting it apart from other similar venues.
"What makes Maze Long Kesh different from other peace centres and other sites of conflict is the juxtaposition of existing prison buildings, which were a focal point of the Troubles in Northern Ireland, with a stunning new building which offers an exciting space for a range of activities concerned with peace-building and conflict resolution," the report by Colliers, which has a base in Belfast, stated.
Mr Nesbitt believes that this revelation should embarrass the DUP.
"The shocking detail reveals that despite DUP assurances to the contrary, OFMDFM's advisers saw the retained prison buildings as inextricably linked to the proposed new centre," the Strangford MLA said.
Colliers estimated that the peace building centre would have had to be subsidised by up to £1m a year depending on the admission prices. The consultancy looked at costings with admission prices running from £4 to £7. This compares to the £15.50 charged for a full price adult ticket to Titanic Belfast, which cost £77m to build.
Colliers recommended that the peace building centre should provide a conference centre for up to 150 delegates, discussion spaces, a peace lab, meeting room, two classrooms, a cafe, and exhibition spaces for both permanent and travelling exhibits. Colliers believed that 45% of the local population would visit, and that it would become a venue for international tourism and conferences.
There would be a separate entrance, and separate charge, for H Block 6, part of the old Maze Prison where terrorist offenders were housed during much of the Troubles and where 10 republicans died on hunger strike in 1981.
The H-Block tour would have included the loyalist and republican wings, inter-denominational chapel, prison hospital and Compound 19, an area showing how paramilitary offenders and internees were held before the H-Blocks were constructed.
TUV leader Jim Allister echoed Mr Nesbitt's anger at Colliers' reports, which were only released after a legal ruling by the Information Commissioner.
Mr Allister was particularly annoyed by the proposed use of the facility as a resource for schools.
"It is also evident that the plans had the potential to warp the minds of future generations with preparations being made to take primary school children to the site," he said.
But Sammy Wilson of the DUP said his party had stopped the plans going ahead.
Analysis: Saga that spotlighted our lack of maturity
The DUP is furious at Mike Nesbitt for continually dragging up the Maze/Long Kesh plans in the run-up to the elections.
That frustration showed in Sammy Wilson's calling on the UUP leader to "apologise for releasing PIRA terrorists" – a reference to the Good Friday Agreement signed by one of Mr Nesbitt's predecessors as UUP leader, David Trimble.
The Maze was ditched by the DUP partly to deny Mr Nesbitt a stick with which to beat it during this election campaign. The DUP felt vulnerable, as opposing unionist parties had some influential victims' groups behind them.
That was one reason why Peter Robinson pulled the plug on what seemed like a done deal. In the process, he plunged relations with Sinn Fein into a downward spiral which still continues.
It is easy to see why unionists would be annoyed by the documents. They talk in one place about 'political prisoners' and make it clear that the Maze Prison buildings and history are part of the site's appeal.
Yet it is important to remember that this wasn't the actual plan for the Maze. It was a commercial report commissioned by the Strategic Investment Board and its findings were never accepted by ministers.
Still, it is hard to escape the feeling that we may have missed a trick and future generations will not thank us for it.
The Maze site would have been a powerful place to draw out the lesions of our troubled past. Unfortunately, maturity and balance are qualities which are so far lacking in this debate.