IT was made for escapism and hedonism, a place to wile away hot summer afternoons beside mirror-like ponds, gentle cascades and classical statues. But the key to Studley Royal Water Garden lies in its follies, whimsical buildings with nothing more in mind than to please the eye.

Perhaps the most famous is the Temple of Piety, which on a still day casts a stunning reflection in Moon Pond. But you don't need good weather to marvel at the art installation currently gracing its interior, because this year the views inside are just as startling.

This is thanks to a new exhibition called Folly! – which transforms the eye-catching temples and follies of the water garden into places of visual trickery and untold histories thanks to three highly inventive artists.

One of them is Simon Costin who invites us to delve into the history, folklore and ancient mythology of the water garden, through a rather bizarre secret held by the late Professor Dennistoun.

The professor had been on a quest to prove a link between a prophesy given by Mother Shipton and the Aislabie family who came to own the Studley estate, which ran: "An ancient place of worship, now in ruin, One family shall come to dwell in. But lest the old un’s are kept entertained, No male heirs shall take the reins."

Dennistoun believed Fountains Abbey to be that ancient place and evolved a strange theory. Unless he could convince the owners of the estate to hold a lavish party in honour of the Old Gods, within what was once called the Temple of Hercules, his three sons would perish.

Costin's 'shrine' is a tribute to that imagined night of Bacchanalian rites, but if you think that's a surprise, wait till you see inside the other follies, visible once more from the water features after a project known as the big reveal, where trees were lopped to offer long lost vistas.

"The garden was cleverly composed so that each view reveals itself and literally leads you round," says Aimee Rawson, the estate's communications officer. "The idea was very much that these were looking out points and now, again, you can see the Temple of Fame from the Banqueting House."

But the view inside is even more extraordinary. Gary McCann's Scavenger explores the relationship between man and nature with a fantastical and gargantuan crow-like bird.

McCann has an innate sense of theatre and is known for his inventive approach to set and costume design. Indeed, his audacious style has led to him producing work for many of the world’s leading theatre and opera companies including the National Theatre in the West End, on Broadway and the Vienna State Opera.

"People confronted by the crow are taken aback, but then they ask about the building, why it's here, looking at the gardens from a new perspective," says Aimee. "With the big reveal you can now see the scale of it all again."

The tree trimming means Surprise View has also been revealed, tempting visitors to scale the upper sections. This folly really did involve theatrics, back in the day, with curtains thrown open to reveal unsurpassed views down the river to Fountains Abbey.

But while you're up there, nothing quite prepares you for the Octagon Tower. The setting is more Italian Riviera than Yorkshire Dales and the Serpentine Tunnel leading to it takes you on a journey into the dark before exploding open in a riot of colour.

Then you go inside.

Irene Brown’s Hall of Mirrors has transformed the tower into a mind-bending world of shifting perspectives and infinite views, turning the idea of follies as viewing points to distant prospects or along carefully constructed avenues on its head.

The artist has turned viewer into subject with mirrors that are evocative of the opulence of the 18th century, epitomised by the great hall at Versailles.

"It's the last thing you expect to see. This was designed for people to look out, now it's completely turned the other way because it's looking in on you," says Aimee."We wanted the whole theme of the garden to be surprising. That's what it was originally designed to be; a theatre set where everything is for show, so it's a perfect setting for these kinds of works."

Folly! runs until November 29 and is part of Trust New Art, a programme created in partnership with Arts Council England to make contemporary arts available in National Trust properties.

Fountains Abbey & Studley Royal is open daily from 10am – 5pm.