The hostess of Wilderness, Lady Rotherwick, tells Tim Hughes why her festival remains head and shoulders above the rest

Since first gracing the lawns of Cornbury Park six years ago, Wilderness has built up a troupe of regular festival-goers, turning up at this most beautiful corner of Oxfordshire every summer.

They come for an extraordinary circus of music, dance, drama, food, wood craft, country pursuits and simply for an excuse to unwind in a wooded landscape that has barely changed for centuries.

Almost 30,000 people are expected at the 2,500-acre estate, on the edge of Charlbury, from today until Sunday – many of them coming back year after year. But of all the festival's admirers, none are more excited than the woman who has made the whole thing possible.

Lady Rotherwick, whose family own the acres of deer park, forest and lakes in which Wilderness has made its home, was instrumental in attracting the gathering to the estate, and for giving them free rein of its dramatic landscape, allowing them to set up the ultimate site-specific event.

And this impossibly elegant country lady remains its biggest fan.

"I love Wilderness!" she says, while savouring the final hours of calm before the first revellers arrive on site today.

"It's my favourite time of year and I can't wait for it all to start. We have a wonderful line-up and I think it will be a great year."

She's not kidding. The line-up is stunning with some musical coups – including Led Zeppelin star Robert Plant, who will play the festival with his Sensational Space Shifters on what will be the only UK date on his 2016 tour, and American alternative-rock band The Flaming Lips, who perform their seminal album The Soft Bulletin.

They will be joined by electro-folk band Crystal Fighters; Grammy-nominated soul-pop singer Lianne La Havas; jazz-house artist Parov Stellar; Oxford lads Glass Animals; and drum and bass DJ Goldie – who performs with the Heritage Orchestra – famous for performing rave and dance classics on classical instruments.

Also up are singer-songwriter Matt Corby, Shura, Tourist, Georgia, Rosie Lowe, Elias and the Hackney Colliery Band, alongside musicians from Ronnie Scott’s and the festival’s in-house symphonic collective, the Wilderness Orchestra – who will present a tribute to David Bowie, along with special guests.

Late-night parties will be hosted in the festival’s secluded valley by Andrew Weatherall, Chicago house maestro Derrick Carter, Jackmaster, PBR Streetgang, Tom Middleton, and Goldie, again.

"There's lots of excitement about Crystal Fighters, Parov Stellar and Lianne La Havas – and they are who I am particularly looking forward to," said Lady R – Tania to her friends – who admits to being a huge music-lover. She has already been to the Love Box and Citadel Festivals in London this summer.

"It's also great to have Glass Animals here, and of course all the bands playing our Juke Joint. There is always something amazing going on."

Tania now bases herself in North Oxford, close to her children's schools, renting out the grand 17th century Cornbury house to tenants, but still intends to do the festival in style.

"We will be camping in a bell tent in the garden," she says. "That way we get the proper Wilderness experience. And because we will be so close to the action, we won't have any choice but to join in, because we won't be getting any sleep.

"The only solution is to dance all night!"

But, she says, Wilderness is about so much more than music, with plays by professional theatre companies in the woods, talks and debates, comedy, boat races in the lakes, early morning cross-country runs, horse riding, yoga and fly fishing.

Then there is the food, with banquets prepared by Oxford’s Raymond Blanc of double Michelin-starred Le Manoir aux Quat’Saisons at Great Milton, Skye Gyngell and Virgilio Martinez; More intimate chef’s table dinners presided over by Christian Puglisi (of Relae, Copenhagen), Robin Gill (The Dairy), Tomos Parry (Kitty Fisher’s) and Lee Westcott (Typing Room); a Moro Souk Tent , and a pop-up catered for by chef and restaurateur Mark Hix.

And that's barely scratching the surface.

"My favourite is Morro," she says.

"The chef's table experience last year was also incredibly delicious. The only problem with sitting down to eat is that there is a risk of missing something wonderful elsewhere. There is too many things to do. You have to be quite strategic in terms of planning.

"The theatre is going to be great this year and the talks and debates will be poignant, topical and very cool."

A measure of the festival's breadth of appeal lies in the diversity of its clientele, with local people rubbing shoulders with Shoreditch hipsters, members of the Chipping Norton set and a smattering of celebrities, who last year included actress Minnie Driver, TV presenter Jonathon Ross, chef Jamie Oliver, and film director (and middle order batsman for nearby Shipton-Under-Wychwood cricket club) Sam Mendes joining the fun.

Even the governor of the Bank of England, Canadian Mark Carney, is a regular visitor, but then he is married to Lady Rotherwick’s sister, Diana, so almost certainly doesn't have to shell out for a ticket.

The estate previously hosted the more stodgy Cornbury Music Festival – affectionately known as 'Poshstock'. When that went into liquidation after seven years, it moved to Great Tew Park, leaving the ground clear for Wilderness's creative team who set about designing a festival specifically for the park's unique topography.

"The creative team are dazzling," says Tania. "I always think this festival can't get any better, and it does.

"I don't compare anything to Wilderness. It stands head and shoulders above every other festival for pure creative magic."

Among the highlights will be Saturday night's set piece spectacle. Previous years have featured trapeze acts and the burning of an ornate tower. Last year, Spanish group La Fura Dels Baus performed a high-wire acrobatic display featuring towering human-like puppets and a living curtain of circus performers suspended on lines from cranes.

"You are transported into a magical wonderland," she says. "There is always something new to see and, hand on heart, you can't fit it all into four days.

"No other festival has that huge array of creativity. And it is designed around to twist around the landscape which is fantastic – with Shakespeare in the forest, dancing in the valley and fire walking by the lake.

"It's so lovely that even my mother loves it. She's 82 now but comes every year, and will certainly be grooving on down this weekend!"

Wilderness starts today and continues until Sunday night, at Cornbury Park, near Charlbury. Tickets and details form wildernessfestival.com