An estimated 430,000 people including 20,000 musicians and dancers have swarmed Derry for what organisers have said is the biggest fleadh ever.

The crowds, which multiplied the city’s usual population by a factor of four, have surpassed all expectations with organisers confident that the seven-day event “will leave a legacy of pride in our culture, and in all cultures who have shared in our joy”.

Fleadh chairperson Eibhlin Ni Dhochartaigh said the Fleadh has been a phenomenal success. The week of festivities began with a successful annual Apprentice Boys of Derry and ended last night with a closing ceremony at the city's restored Ebrington Square on the Waterside.

She was among those taking the stage at the ceremony alongside Deputy First Minister Martin McGuinness, Mayor of Derry Martin Reilly and Labhras O Murchu Ard Stiurtheoir of Comhaltas Ceolteoiri Eireann.

The ceremony at the former Ebrington headquarters of the British army in the city and the barracks used by the Parachute Regiment on Bloody Sunday 1972 marked the culmination of festivities launched by President Michael D Higgins last week.

Ebrington has now been restored to public use as a cultural centre and public performance space and is linked to the Cityside across the Foyle by the new EU-funded Peace Bridge

Mayor Martin Reilly said the event had been “a phenomenal success”.

“Many a first has been achieved this week both in terms of the city hosting an event of this scale and one which has exceeded all expectations in terms of visitors to the city,” he added.

Derry, he said, “has a renewed sense of civic pride and can boast hosting a safe and enjoyable event one which has been embraced with community and business support. I want to extend an open welcome to those who were first time visitors to Derry to return.”

Shona McCarthy, chief executive of the Culture Company 2013 which is charged with delivering the City of Culture year in Derry said: "Fleadh Cheoil na hEireann is always a special experience but this year as it came North for the first time and was hosted by a city for the first time, and in the context of an extraordinary year for Derry, it has been magical."

More than 2,500 people attempted a new world dance record by performing Riverdance yesterday afternoon. The record attempt will not be officially confirmed by the Guinness Book of Records for a few weeks, but organisers and local charity Children in Crossfire believe they have done enough to claim the title.

The fleadh has exceeded income and business targets and organisers are confident the upturn in confidence will long outline the week’s events in the city.

"About 1,000 full and short-term jobs have been created thanks to this week and the UK City of Culture year so far," said Sharon O'Connor chief executive of Derry City Council. "Hotels are reporting a 32 per cent rise on this time last year."

“There are 40 new businesses in the city so far including a new hotel. But more important than that are the results of the public attitude surveys. We’ve been told that 96 per cent of the people of this city are much happier and more positive about the future.”

The levels of public involvement in the City of Culture events including the fleadh so far this year suggest also that all communities in Derry and beyond have bought into the idea of a shared cultural celebration.

Mayor Reilly mixed with the large crowd who thronged his parlour which was open to the public in the Guildhall yesterday afternoon. More than 12,000 people visited the restored Guildhall on Saturday, a one-day record, while thousands more mingled outside. It served as the nerve centre for the fleadh competitions and the dozens of competition results have been carefully collated and posted on the fleadh Facebook page.

Overlooking Guilhall Square, the city walls were packed with visitors and musicians while Shipquay Street and the Diamond were solid with crowds.

Ms O’Connor said the task of the city council was to ensure that the fleadh and the City of Culture year were more than just money-spinners.

“We really want to create a better future here,” she said. “We’re not waiting for anyone to come to make it for us. A lot of people have negative images - when they think about Derry they think about the past so we really are out to show them a Derry that is full of colour and opportunity.”

Referring to the thousands who had not been North before she said this would live on as the fleadh’s legacy.

“There is no mystery about what the formula is here. There have been decades of investment in relationship-building, in communications, in trust, in confidence-building. It is a tribute to the people on both sides of the so-called divide. It’s a long-term investment and it’s a tribute to the people here that years of building a consensus has culminated in a week where we started with a wonderful Apprentice Boys celebration and ended with the biggest all-Ireland Fleadh that has ever been.”