Daily audiences of 50,000 people are expected for the fourth annual Witnness music festival in Punchestown racecourse, Co Kildare, this weekend.
The two-day event will feature more than 100 performers. The organisers say some tickets are still available for the festival which sold out last year.
In a bid to diffuse the traffic jams which have become a predictable feature of the event, music fans are invited to begin arriving at the on-site camping grounds from noon on Friday.
There will be pre-festival entertainment from two DJs and Jerry Fish and the Mudbug Club on Friday. The headline acts for Saturday and Sunday are Coldplay and David Gray, while other performers include Badly Drawn Boy, Supergrass, Super Furry Animals, Lemon Jelly and Beth Orton.
Workers were yesterday completing on-site construction of the five large stages, five bars (including a waiter service VIP bar "for everybody") and countless portaloos.
The sponsors say the amount of electricity being used to run Witnness would supply the needs of residents of the Aran Islands for two years, while the organisers estimate it is worth more €8 million to the economy.