Green Man festival in the Brecon Beacons to attract 25,000
About 25,000 music fans are to attend the Green Man festival in the Brecon Beacons which starts on Thursday.
The four-day event, in its 16th year, is a sell-out, with acts including The War on Drugs, Fleet Foxes and Public Service Broadcasting performing.
The independent festival is funded via income rather than sponsorship and there has been interest from big companies to take over Green Man.
Managing director Fiona Stewart says the event is "very attractive".
"There has never been such a brutal time in the festival industry," she told BBC Radio Wales.
"It's one of the few independents left and we sell out early so it's a very attractive option to big American, international companies."
But she stressed her team's commitment to keeping the festival near Crickhowell in Powys independent, adding they wanted to be able to offer the public something that's free from being "sold".
The event on the historic Glanusk Estate includes an area selling independently brewed beers and ciders, an area for children and Einstein's Garden - a celebration of science, art and nature.
"What I love about Green Man is that it enables people to choose their own festival experience," added Ms Stewart.
"They can dance all night, watch comedy or late-night films, or sit in a hot tub drinking bubbly, drink a craft Welsh ale or discover a new band and then go and see an international headliner."
Motorists are warned to expect heavier than normal traffic on the A40 between Abergavenny and Brecon and on the nearby A465 Heads of the Valleys road.
There will also be shuttle buses running from Abergavenny train station.
Revellers are also set to be bussed in on special coaches from 30 locations around the UK.