Jose Carreras and Joan Baez are headlining this year's event

One of the highlights of the event's first day is an evening concert by American folk singer Joan Baez.

The festival will end with tenor Jose Carreras performing on Sunday.

Eisteddfod chief executive, Gwyn Williams, said: "We're anticipating breaking all records, with more people on site than ever before."

Mr Williams said the recent bad weather had done nothing to dampen ticket sales.

He added: "I think it's really worked in our favour. People have been pinned down at home for weeks now because of the bad weather, and now it has brightened up.

"Sales remained constant, even despite the bad weather. The numbers are up for every day."

Mr Williams said he met a group who spent three days driving across from Croatia.

"They took a wrong turning off the M5 and ended up in Llandovery, not Llangollen, so they had quite an extended journey getting here, but they've arrived and that's the main thing!"

Former Middle East hostage Terry Waite is to visit the WWF Cymru stand between 1400 BST and 1600 BST on Wednesday for the launch of the charity's carbon footprint calculator.

The eco-test calculates the environmental impact of people's lifestyles on the planet.

Tibetan monks

Other highlights of the eisteddfod - which runs from 10-15 July - include a concert by classical artist Hayley Westenra on Friday.

As in previous years, International Children's Day is expected to draw big crowds, with performers from countries including Taiwan, India and Spain.

A group of Tibetan monks will also perform Buddhist chanting and dances.

Friday has been designated as International Celtic Day, focusing on folk dances and choir concerts.

Saturday will see local children deliver the traditional message of peace and goodwill from Wales to the world as part of International Family Day.

Takings

The Eisteddfod began in 1947 and now hosts between 2,000 and 5,000 competitors every July.

In 2006, audience numbers rose to 45,000 - an increase of 17% on the previous year.

Takings rose to �530,000, netting the charity an extra �90,000, and creating a surplus for the fifth year running.