St Patrick’s Church has been standing on Donegall Street in Belfast since 1877.
The building withstood the Belfast Blitz during World War Two and recovered from a catastrophic fire in 1995.
But its distinctive stone cladding exterior is now struggling to hold off the ravages of weather and time.
And millions of pounds will be required to carry out restoration work, according to the church administrator.
Father Eugene O’Neill said the time has come to “refresh the fabric” of the distinctive building.
“It’s a stone building and it has 140 years of Belfast soot and dirt and corrosion eating into it,” he said.
In recent months, work has been completed on restoring the top end of the church spire at a cost of £1m.
The next phase of work will cost at least £2m.
“One third of the church spire was a million pounds but we had to stop when we ran out of money about one third away from the top,” Fr O’Neill said.
“Now we need to raise funds to complete the tower.
“Then after that, raise more funds to complete the restoration of the fabric of the church.”
That would involve replacing worn stone, windows and other parts to make sure the building is still standing in another 140 years.
Ian Whoriskey has been the sacristan at the church for the past three decades and has observed the crumbling damage to the outside facade.
“Over the years the stonework has decayed and parts of it were falling down around the side and the front of the church.
“It was dangerous – some pieces were as big as bricks.
“We had to get a steel-mesh net put up to safeguard people coming in and out of the church.”
Prince Charles visited St Patrick’s Church two years ago and later donated £2,000 towards the restoration works.
But much more than that will be needed, and Fr O’Neill said “alternative sources” for funding are being sought.
The church is hoping to tap into the “generosity of Catholics in the United States”, he said.
“If we were to try to build that today, it would cost us probably in the region of £10m to £15m to put up,” he added.
“Let’s remember, it was built in 1877 with the pennies of the poor – there were no wealthy Catholics then.
“Many tens of thousands of people contributed small amounts to help build it.
“We’re expecting that we’re going to have to ask for funding from our parishioners and Catholics further afield so that we can restore it.”
St Patrick’s has been the centre of some controversy over parading in recent years.
But, that issue appears to have passed this year.
And Fr O’Neill said the church is now looking to the future and playing its part in the huge economic development taking place in the surrounding area.
“The major funder [of the nearby development] is the Ulster University, which is putting in about a third of a billion pounds into a vast new campus.
“That will effectively wrap itself around our church in glass and steel and provide a very stimulating and futuristic backdrop to our Victorian gem of a church.”
He believes the church will be a “beacon of hope, civility and faith” for the student population that will soon arrive in the area.
The redevelopment is a sign that the “scars of the Troubles” in north Belfast are being “healed”, according to Fr O’Neill.
It could soon become a “boom town”, he added, with St Patrick’s at its heart.
“St Patrick’s is a very beautiful church and I think it will continue to be a haven for peace and reflection.”