Planning permission is being sought from Dublin City Council for two of the tallest buildings yet proposed anywhere in Ireland - and both of them would be even higher than the Spire in O'Connell Street.
The two glazed towers are the key elements of a Digital Hub scheme by Manor Park Homes (MPH) for a 2.5-acre site on Thomas Street in the Liberties, between St Catherine's church and the Guinness Hop Store.
Designed by award-winning architects deBlacam and Meagher, the tallest of the towers would be 171 metres (564ft) high, making it nearly three times the height of Liberty Hall - the city's tallest building.
With a helicopter pad at roof level, the proposed tower would rise 47 storeys from a podium, which in itself would be four storeys high. It would contain a 360-bedroom hotel, with 80 serviced apartments on upper floors.
The second tower in this "mini-Manhattan" project would be 124 metres (409ft) high - three metres taller than the Spire - and would contain 33 floors of offices designed to accommodate digital technology companies.
The podium on which the towers would stand is envisaged as a lively space, animated by having creches, bars and restaurants opening onto it. Its centrepiece would be a circular landscaped area, with walkways.
On the Thomas Street frontage, a series of five eight-storey blocks would be inserted between protected historic buildings. Their design echoes deBlacam and Meagher's award-winning Wooden Building in the west end of Temple Bar.
A stone staircase, six metres wide, would lead up from the street to the podium level. Beneath the podium, a brick-vaulted gallery - 140 metres long - would extend right through the site, and would be lined with food courts and other retail outlets.
According to Shane deBlacam, the scheme was inspired by Aurora Place in Sydney, Australia, which was designed by Italian architect Renzo Piano. It also consists of two tall towers and "lifts everything else in the city around it", he said.
"There's no reason why Dublin shouldn't have a skyline like that, with slender towers sticking up to great heights. The history of architecture is about putting buildings on a hill" - a reference to the fact that Thomas Street is on a ridge.
Asked why they had departed so radically from the relatively modest heights envisaged in the Digital Hub master plan, Mr deBlacam said its densities were "at the lower end of what Dublin could take" and this was about "real regeneration".
MPH's planning consultant, Stephen Little, said there was a "tradition" of tall buildings in the Liberties, citing the nine-storey Guinness Storehouse as a precedent. The Digital Hub was also part of a strategy of moving the city centre westwards.
Alan Sherwood of TDI Consultants, who have been advising on the scheme, said it had been tailored to the needs of firms employing up to 20 people who wanted offices with small floorplates in buildings with "soul".
On the central issue of its soaring heights, John Moran - MPH's development director - pointed out that the city council's planners had granted permission for a 12-storey tower in nearby School Street, "so we're not the ones who broke the glass".