The Taoiseach has opened the new Moore Street Plaza on the historic inner-city street renowned for its colourful stalls and the cries of Dublin street traders.
Mr Ahern unveiled a plaque on the site before moving indoors to open the new Jury's Inn Hotel on the plaza.
In the man-of-the-people style for which he is famous, the Taoiseach posed for pictures with Moore Street traders as a group of curious and hard-hatted builders looked on.
Builders elevated on a scaffolding across the road cheered and made tired "politician" jokes which the Taoiseach studiously ignored - although he acknowledged the builders with a smile and a wave.
The construction workers, in the traditional "mating" ritual of all builders, then contented themselves with loudly wolf-whistling at a woman attending the hotel opening.
Trader John Draper posed with the Taoiseach, who held a bunch of flowers for the photographs. However, Mr Draper quickly retrieved the flowers from the Taoiseach's entourage afterwards.
Speaking to invited guests at a lunch in Jury's Inn, Mr Ahern noted the transformation in the area, which just a few short years ago was a derelict site, he said.
He said the new development, coupled with the redevelopment of the ILAC Centre and the former Walden Motors site, would draw shoppers and visitors beyond Henry Street into Parnell Street in the years to come. The new jobs created would bring a renewed sense of prosperity to the area.
Mr Ahern said it was "only right" that this area of the city should be the focus of regeneration.
"For decades, Moore Street has been synonymous with street trade, with colour and with a particular vibrancy. There is a great sense of vitality attached to the street.
"That vitality is coupled today with an ever-increasing diversity, which captures the changing face of Ireland." The development added a new dimension to an area that had become "run down" in recent years, he said.
The development is the first to be completed in the area, which has been offered special tax breaks in recent years to promote regeneration.
Mr Richard Hooper, chairman of the Jury's Doyle Hotel Group urged the Taoiseach to work "whatever magic you have" in order to move forward the plan for a national conference centre close to the site. "You have a little magic wand in there somewhere," he said.
Mr Garrett Kelleher, chairman of Shelbourne Development Ltd, which constructed the new plaza and hotel, also referred to the national conference centre in his speech, noting that "some day soon" the adjacent Carlton site would "take off".
The project, originally earmarked for the site of the old Carlton Cinema on O'Connell Street, has been fraught with difficulty and delay for more than a decade.