THE 30th Hay Festival has got underway in Hay-on-Wye with big name politicians, stars of stage and screen and a royal visitor visiting the festival site.

However first on site were more than 3,000 primary school children from across Wales who attended the festival’s school days event on Thursday with secondary school pupils attending on Friday.

Prince Charles’ wife Camilla also toured the festival site on Friday while former deputy PM Nick Clegg was among the headline speakers.

The festival, which runs until Sunday, June 4, features more than 500 speakers in over 600 events.

This Saturday US senator Bernie Sanders, who lost out to Hilary Clinton for the right to be the Democrats’ presidential nominee, will be appearing at the festival.

UK politics watchers will be waiting to see if the self-declared socialist will offer any words of encouragement to Labour leader Jeremy Corbyn. Mr Sanders will also record a special edition of the BBC News channel’s flagship current affairs programme HARDtalk at the festival site.

Welsh actor and activist Michael Sheen is also delivering the Aneurin Bevan lecture on Saturday.

Former Labour chancellor Ed Balls appeared at the festival on Saturday and discussed the infamous 1994 ‘Granita’ restaurant meeting between his former boss Gordon Brown and Tony Blair, where the pair are said to have reached agreement over the control of the Labour Party.

After losing his seat at the 2015 election, Mr Balls turned to reality TV as a contestant in the BBC’s Strictly Come Dancing show, which the audience also wanted the inside gossip on.

Olympic diver Tom Daley shared the secrets of his fitness and motivational routines while actor Richard E Grant and Blackadder’s Baldrick, Tony Robinson, were among the stars reading memorable letters in the Letters Live series.

Former Russian chess grandmaster Garry Kasparov spoke with festival president Stephen Fry about his experience losing to IBM super computer Deep Blue 20 years ago – and how he shared his experience to help develop artificial intelligence.

Could the appearance of artist Tracey Emin at the festival explain why a pyramid of books appeared in the river Wye?

The controversial artist, famous for her unmade bed entry in the Turner Prize competition, appeared on Sunday to discuss her work and inspirations with GQ editor Dylan Jones.

Over the weekend a small mound of books, in the shape of a pyramid, appeared on rocks in shallow water on the banks of the river underneath the Hay Bridge. All of the books have titles that appear to be related to self-help or self improvement, such as The Joy of Success and Change Your Brain while one has Psychobabble printed on the spine.

Local angler Jeff Morgan, who took a photograph, was unimpressed. He said: “This is environmental vandalism masquerading as an art installation in the River Wye below Hay bridge.

“Lots of local people who work hard to keep the river litter free are really annoyed by this.”