The Giro D'Italia is crossing the border today as 200 of the world's best cyclists gear up for the final Irish stage of the famous Italian race.
Stage 2 gets underway in Armagh at about noon and will see the riders speed through 187 kilometres, ending up in Dublin's Merrion Square by 5pm.
Hundreds of thousands of people sporting pink for the occasion have already begun to line the routes through Dundalk, Drogheda, Balbriggan, Malahide and Clontarf.
Some 775 million people around the world will be watching the race on TV.
Minister of State for Tourism and Sport Michael Ring said it was the kind of publicity you "just can't buy".
"It's going across 174 countries, reaching 125 million householders and a TV audience of 775 million," he said.
"It's a great opportunity for Ireland to sell its natural beauty. It's the kind of publicity we wouldn't be able to buy, either Tourism Ireland or Fáilte Ireland. It's an opportunity to sell Ireland."
Road closures and diversions will be in place all along the Giro route from Armagh to Dublin, so spectators are advised to get to their vantage points early and use public transport where possible.
Irish Rail are putting on extra commuter services as well as extended DART times.