The hall is an impressive riverside structure, all glass and metal, built in 1997 as a symbol of the city's economic regeneration. It projects modernity, confidence and innovation.
Its huge windows offer glimpses of west Belfast, where most of the city's Catholics live; they also give views of where the Lagan river leads out to the rest of the world.
Inside the Waterfront yesterday David Trimble was in the business of persuading his traditionally doubting and conservative party to be more outgoing and to update its relationships with the outside world. In particular he advocated a new deal with the political representatives of those west Belfast Catholics, Sinn Fein.
He succeeded by a margin of 480 votes to 349, not quite a comfortable majority but enough to proceed tomorrow with the formation of a government which will include Sinn Fein. A win is a win but the dimensions were such that he will forever need to keep looking over his shoulder.
His securing of 58 per cent of the vote would be enough to settle most issues, but this is different. It sets his party on a new path, altering as it does its fundamental approach.
No longer are republicans to be regarded as pariahs: now they are accepted as fit partners in government, albeit on a type of political probation, subject to good behaviour and movement on de-commissioning.
It was clear yesterday, from the small but noisy knot of people outside the hall who jeered and called out "traitor" at Mr Trimble and his supporters, that there will always be some opposed to any deal, whatever safeguards are built into it.
A pessimist can point that many more hurdles lie ahead with much uncertainty still in the air. The Ulster Unionist Party will review everything again in February, and if by then there is no de-commissioning the threat is that it will pull its members out of the new government.
The optimistic theory runs that, by then, devolution of power will have become a reality rather than an abstract notion, and that both the Unionists and republicans will deliver new concessions in their desire to preserve the fledgling government.
Given all this, the likelihood is that a Belfast version of a brave new world will come about, and get through the inevitable crises and turmoil ahead. Nearly all the nationalists want it, and more than half of the Protestants do, too.
But yesterday's vote also confirms that a substantial Protestant rump remains impervious to all the visionary rhetoric and talk of historic new beginnings and bright new dawns. The 42 per cent who voted against the Trimble plan seem determined to remain, psychologically at least, back in the Ulster Hall, the original venue for yesterday's meeting. That hall is a slightly run-down, old-fashioned building in the city centre which is closely associated with traditional Unionism. It was here in 1886 that Lord Randolph Churchill urged thousands of Protestants to resist Home Rule, declaring: "Ulster will fight and Ulster will be right."
In 1912 it was one of the venues used by Edward Carson and other Unionist leaders to express Unionist determination to assert tribal rights. It is a citadel of a Unionism which defined itself as Protestant, Orange and exclusive.
Those 42 per cent clearly see moving to the Waterfront as too risky. Mr Trimble's project is the political regeneration of Unionism, arguing that the union with Britain is better preserved through modernisation than by the Ulster Hall's brand of splendidly defiant isolation. He has persuaded enough of his party to be able to proceed, but there are plainly many unreconstructed traditionalists out there in the party rank. This means that Mr Trimble's flanks are always going to be subjected to harrying actions both from the Rev Ian Paisley and from his own internal critics.
At the same time many of those who are backing the Trimble approach are doing so not with whole-hearted enthusiasm but as something of an experiment. This in turn means the survival of the peace process can never be taken for granted. There is enough support for it to continue, but not enough for confidence that it will survive the many tests ahead.Reuse content