Andrea Bocelli sang at a sell-out Sunday concert

A total of 25,000 people attended the first three nights, with some travelling from America.

Sunday's opera performance with Terfel and Italian tenor Andrea Bocelli was a sell-out, with an audience of 12,000.

Organisers said there were "no real problems" with alcohol and the policy of banning bar sales to those under 21 had proved a success.

"The performances were brilliant, the audiences were fantastic, it didn't rain - the gods were truly on our side," said festival spokesman Joe O'Neill.

On the eve of the festival, North Wales Police issued a warning about underage drinking.

They said if under 18s broke the law, as they did at last year's festival, it could mean no licensed bars at the site in future events.

Festival organisers brought in a ban on alcohol for those under 21.

Classic, rock and pop

Mr O'Neill said: "It's easy to look 18 when you're younger, but impossible to look 21 - so that policy has been quite effective. There were no real problems to report."

The festival attracts thousands and had Snowdonia as a backdrop

He added: "As far as the festival is concerned it really is a case of onwards and upwards. The planning starts now for the seventh festival next year."

The festival, which began on Friday night, featured stars from the classical, rock and pop music worlds.

Van Morrison, Alison Moyet and Katherine Jenkins joined this year's line-up.

Organisers said 7,000-strong crowd turned up to watch Neath-born mezzo soprano Jenkins on Friday night.

Ticket sales were the highest they had ever been, with Sunday night's performance by Bocelli selling out two weeks previously.