One of the world's top professional cycling races will put Northern Ireland's north coast on the map, organisers said.
The three-day start of the Giro D'Italia in May will pass dramatic Atlantic breakers and the Unesco World Heritage site of the Giant's Causeway.
Up to 140,000 spectators could attend.
Time trials will be held in Belfast, taking in the stately home of the Northern Ireland Parliament at Stormont, before a final leg from the ecclesiastical capital of Armagh to Dublin.
Darach McQuaid, the inspiration behind the event, said: "We want to make the Causeway Coast one of the must-do cycling routes for any serious cyclist around the world.
"We really want to turn this into an iconic location for cyclists around the world."
More than 200 of the world's elite riders will take part.
Mark Cavendish, one of the most successful sprint time trial competitors in the Tour de France who was voted BBC sports personality of the year in 2011, could be among star names.
Tourist authorities anticipate that the event will attract 42,000 visitors from outside Northern Ireland.
Mr McQuaid, who represents local organising company Shadetree Sports, said the Giro had an important role in Italian heritage.
"It has weaved its way in and out of Italian landscape and its psyche and history. It is like riding the history of Italy," he added.
"It is a cultural gift to somewhere like Northern Ireland to bring their beautiful event to Northern Ireland."
The Causeway, a series of hexagonal basalt rock columns to which local myth is attached, was lit up when the Olympic torch was carried through it in 2012.
Mr McQuaid said the weather could be challenging for competitors, particularly if strong winds buffet the riders. He added their response could be spectacular.
"It is like somebody has dropped a bit of TNT (explosive) into the riders. All of a sudden they can spread all over the road."
It will be a major policing operation, a "bubble" will be created around the competitors and there will be disruption, police warned. A final figure for the number of officers has not been decided.
Police Service of Northern Ireland (PSNI) chief superintendent Alan Todd said: "It will be a big commitment. You cannot bring a world-class event anywhere unless you are prepared to support it.
"You have to make it safe."
He added it was about ensuring Northern Ireland's legacy as a place to hold these events.
"It is about playing our part in Northern Ireland PLC."
Northern Ireland is to bid to hold an amateur race linked to the Giro from 2015, the Fondo, which can also attract large numbers of enthusiasts and visitors.
This year's Giro Big Start in Northern Ireland runs from 9-11 May.
Eurosport viewers from 165 countries will be watching.
Day one involves a 21.7 km time trial around Belfast from the Titanic Quarter where the famous liner was built to the City Hall. Day two is a 218 km loop starting and ending in Belfast, including the Causeway coastal route. Day three is a 187 km ride from Armagh, known as the Cathedral City because the Church of Ireland and Catholic Church in Ireland have headquarters there, to Dublin.