National Eisteddfod: Ticket sales hit by technical hitch
"Technical difficulties" have caused delays for people buying tickets for this year's National Eisteddfod.
Some have taken to social media to express their frustration at not being able to book tickets for events.
The Wales Millennium Centre, which is selling tickets for the arts festival, has apologised for the disruption.
The National Eisteddfod also apologised on Twitter, saying the centre had experienced "technical difficulties" and "high volumes" to its website.
It continued: "Keep trying and thank you for your patience!"
The initial technical problem has been resolved and the Wales Millennium Centre says it has its "teams working hard on the phones".
Tickets went on sale for the event in Cardiff at 08:30 BST.
Sarah Nicholas said on Twitter: "I've got through on the phone 18 times, but I'm always cut off.
"I'm really, really sad about this."
The National Eisteddfod said the booking process was still slow, but encouraged users to "please persevere".
The Eisteddfod will be held in Cardiff from 3-11 August.