All roads will lead to the racecourse this weekend, with a music festival set for Punchestown, Co Kildare, and some more traditional racing fare at Fairyhouse, Co Meath.
Thousands will travel to the long sold-out Oxegen festival at Punchestown throughout the weekend and gardaí have put a traffic management plan in place.
Bands set to kick up a super-loud soundstorm in the Kildare area include Foo Fighters, Green Day, New Order, the Killers, the Prodigy and Queens of the Stone Age.
For weather-watching festival folk, Met Éireann says tomorrow will get off to a cloudy start with a few bright or sunny breaks developing later in the day. It will be dry apart from a little drizzle here and there and it will be warm, with temperatures reaching up to 23 degrees in parts. The weather will become increasingly warm during Sunday.
AA Roadwatch warns that long delays are likely on the key routes approaching the venue tonight, tomorrow and on Sunday.
"Traffic is expected to be particularly heavy on the main N7, M7 and N81 heading to the site," said AA Roadwatch controller Emma Caulfield.
The campsite opens today at 1pm, and the promoters recommend that ticket holders arrive early. Ticket checks will be in place on the approach routes and anyone without a proper ticket will be turned back.
Dublin Bus will operate a shuttle service every 20 minutes from Parnell Square from noon to 7pm today, from 10am to 5pm tomorrow and from 11am to 4pm on Sunday. There will be return services immediately after the event each evening.
Bus Éireann is also running a service between Naas and Punchestown during the festival.
Traffic delays are also likely in Waterford until tomorrow as the Tall Ships Race continues. Diversions are in place as the quays are closed to all traffic.
Tullamore is the venue for another spectacle this weekend as the Enfer World Sheep Dog Trials continue at Charleville Estate. The major event has attracted competitors from 21 countries and nearly 250 sheep dogs and their handlers will take part.
The grand final takes place on Sunday and around 30,000 people are expected to visit the event over the weekend. Family activities, a food and drink village and traditional Irish music and dance will provide the backdrop for the trials.
On the sporting front, Dublin play Offaly in a Guinness All-Ireland Hurling Championship match at Parnell Park on Saturday evening. Throw-in is at 7pm, and there will be traffic delays in the Donnycarney and Malahide Road areas around this time and after the match.
On Sunday, Armagh and Tyrone will do battle at Croke Park in the Ulster Senior Football Championship final at 3.30pm.
Cork and Kerry will play in the Munster Senior Football Championship at Pairc Ui Chaoimh at 4.15pm.
Upgrade works on the Dart line continue at the weekend on the south side of the line, and there will be no services south of Connolly. Passengers travelling through Dublin airport should arrive at least 90 minutes before their flight due to additional security checks.