Over 80,000 people are making their way to Slane Castle for a sold-out Harry Styles concert.
Fans were advised to treat the Co Meath venue like going to the airport and to give themselves around three hours' travelling time.
This includes a 45-minute walk to the site from the four car parks, with colour-coded routes for ticketholders to make their way to the event.
There will also be airport style security, but reusable water bottles will be allowed in.
Ground conditions in Slane were described as perfect, but organisers have said it was not "stiletto ground".
Read more: Preparations under way for Styles gig at Slane Castle
While warm and dry weather is forecast, people were urged to wear appropriate footwear and bring clothes for the evening time when it gets cooler.
Gates opened at 2pm, with the first act due on stage at 2.30pm.
Tickets for the "Love on Tour" concert must be downloaded in advance, so people should ensure to keep their phones fully charged and bring battery packs.
It is the first gig at Slane Castle since Metallica played in 2019 and the first post-pandemic concert at the venue.
More than 300 gardaí will be policing the gig and all roads into Slane were closed from this morning.
