The tallest round tower in Ireland, named after of one of the country's most important statesmen, has re-opened for the first time in nearly 50 years.
O'Connell Tower in Dublin was built in 1855 to commemorate the Irish nationalist leader, Daniel O'Connell.
He led the campaign to end religious discrimination against Catholics, who had few rights in early 19th Century Ireland.
The tower shut in 1971 when it was damaged by a loyalist bomb but recently it has undergone extensive renovations.
The monument stands at 55m (180ft) in Glasnevin Cemetery in north County Dublin, where it commands "breathtaking" 360 degree views of the city and neighbouring counties.
Four windows at top face north, south, east and west - looking out towards Meath, Wicklow, west Dublin and the Irish Sea.
Its original wrought iron spiral staircase was extensively damaged during the Troubles when a 4.5kg (10lb) gelignite bomb detonated near the base.
The explosion was blamed on loyalist paramilitaries from Northern Ireland, in a suspected reprisal attack for the 1966 republican bombing of Nelson's Pillar in Dublin city centre.
The main structure survived but the blast caused the steps, made up of the main spiral staircase and higher flights of wooden stairs, to collapse.
"It blew up the innards, blew out the windows, the crypt was just full of rubble, but the tower itself stayed in place," said the chairman of the Glasnevin Trust which looks after the cemetery.
"The tower was moth-balled, we just didn't have the resources to reopen it," John Green told BBC News NI.
A clean-up operation began in the 1990s and in 2009, the ornate marble crypt was officially reopened by the then Irish President Mary McAleese, but the tower itself remained inaccessible to the public as there was no safe method to get to the top.
Two years ago, a major project began to repair the tower and reinstate the 222-step staircase.
The project used the "original plans and traditional methods employed by the carpenters and skilled tradesmen who first constructed it", according to the trust's website.
They mirrored the work of the "hundreds" of labourers and tradesmen who were involved in building the tower more than 160 years ago.
"It was more complicated than we thought", admitted Mr Green.
"The tower narrows as it goes up and the gaps between the landings reduce... so everything had to be individually measured."
The chairman added that when the tower opened in the 1860s, its builders were not constrained by today's public safety legislation.
"So, you're putting in a 19th Century set of stairs but you have to take into account the 21st Century requirements, particularly in health and safety."
'Level of fitness'
The renovated tower, which was officially reopened on Friday, includes a new exhibition telling the story of Daniel O'Connell.
Up to 40 visitors an hour will be able to climb to its lofty peak, although the trust advises members of the public that it will require "a reasonable level of fitness".
The original construction began in 1854 - seven years after O'Connell's death - and the limestone and granite tower took 16 months to complete.
It cost £18,000 at the time, a figure which the trust estimates would equate to 15m euros (£13m) in today's money.
The builders carved a hole in its foundation stone and placed in it a lead time capsule containing artefacts and medals relating to O'Connell's life.
The crypt beneath the structure contains the statesman's remains, except for his heart, which was buried in Rome in accordance with his dying wishes.
O'Connell, known as the Liberator, is remembered as one of the most significant figures in Irish history.
He is revered as a human rights activist who abhorred violence; a highly influential political leader and renowned public speaker.
"O'Connell was important to our history because he had a vision, which was an inclusive vision for the whole of Ireland," said Mr Green.
"He worked for all the people on the island and even though he was thwarted in that, he set us out a pathway to that vision which was a peaceful parliamentary political process.
"That beacon has been carried on by (Isaac) Butt; by (Charles Stewart) Parnell; by (John) Redmond and then by each and every taoiseach (Irish prime minister) since the Civil War.
"It was his model of how to progress, his ability to negotiate... he was an amazing achiever."
The nationalist politician was also famed as an outspoken critic of slavery and Mr Green said on that subject his "worldwide reputation at the time was quite extraordinary".
O'Connell was born in 1778 to a Catholic family who had been dispossessed of their lands near Cahirciveen in rural County Kerry.
Public office ban
He was educated at a Catholic college in France, before going to London to study law, becoming a barrister in his early 20s.
At the time, Catholics living under British rule in Ireland were banned from holding most public office and could not sit in parliament.
In 1801, the Act of Union abolished the Irish Parliament in Dublin and subsumed it into Westminster.
O'Connell put his formidable debating skills to use, arguing for Catholics to be given the same political rights and civil liberties as Protestants, forming the Catholic Association campaign group in 1823.
In 1828, he won a Westminster by-election to represent County Clare, but was prevented from taking the seat because of his religion.
However, his election victory and rising influence in Ireland helped to pressurise the British government into passing the Catholic Emancipation Act the following year.
The legislation ended the ban on Catholic MPs and O'Connell took his seat in Westminster.
The nationalist MP remained opposed to the Act of Union and began to organise large rallies in Ireland calling for the return of the Dublin parliament.
In 1841, O'Connell was elected as the first Catholic Lord Mayor of Dublin, but continued to hold his seat in Westminster until his death.
He died in Italy in 1847, while making a pilgrimage to Rome at the age of 71.
He was buried in Glasnevin cemetery but his remains were exhumed and reinterred in the crypt beneath the tower in 1869.
Friday's official reopening was attended by the Irish Minister for Finance Paschal Donohoe and Northern Ireland MP Sir Jeffrey Donaldson from the Democratic Unionist Party (DUP), among others.
A second time capsule was placed in the based of the tower by students from the O'Connell School in Glasnevin.
The first public tours began on Saturday.