If you were to venture down Cynthia and Paul Kiley’s driveway at Piccadilly, you might think you’ve accidentally taken a wrong turn into the Mount Lofty Botanic Garden.

Rows of mature plain trees stand either side of the driveway; a green corridor dissecting the couple’s well-established and quintessentially Adelaide Hills garden on more than 11 hectares.

However, the beautiful stone Yangennanock homestead is unmistakable.

More than a century and a half old, the property is in immaculate condition with four bedrooms, two bathrooms, a heated infinity swimming pool and full-sized equestrian arena.

Cynthia and Paul have listed the property for sale in order to downsize, with their two sons now in their late 20s and Cynthia’s equestrian commitments taking her interstate. She is currently training with the Victorian amateur dressage squad.

Paul is a finance professional in the mining industry and is a keen cyclist, who regularly cycles the 17 kilometres from Piccadilly to his office near the Adelaide CBD.

Cynthia worked as a nurse for more than 30 years, studied interior design when she lived in the United States and also has a degree in horticulture and a passion for gardening.

“It’s just a utopia, yet we’re only 17 kilometres from the CBD,” Cynthia says.

“We live this incredibly rural lifestyle because it’s quite secluded; it’s got a special feel to it. It’s just too big for us now.”

The motivated couple has bought and renovated multiple properties over the years, including their previous home at Stirling, and their beach house at Middleton.

Over the past four years, Cynthia has also been renovating a dilapidated country homestead in Victoria.

“I’ve got lots of irons in the fire,” she says. “We can’t help ourselves! For me it’s a passion; I love it.”

“We’ve recently found a little old 1950s beach shack down at a place called Cape Bridgewater in Victoria, so I’m going to go and do that up.”

Voracious travellers, Cynthia and Paul met in Aspen, Colorado, and would spend their winters in the Rocky Mountains and summers in Europe. It was in the States that Cynthia fell in love with American barns and homesteads, while she was doing a lot of riding there. Her love of American country homes is reflected in her property.

However, it was the Adelaide Hills that lured them to set down their roots. “This the longest we’ve ever lived at one property in our entire lives,” Cynthia says.

When the couple purchased Yangennanock two decades ago, it was a far cry from the gorgeous property and manicured gardens that exist today.

“We were living in Stirling, but I wanted a bit more land for the horses. We found this property and it was on the middle of the paddock — it has quite a long driveway down to the house,” Cynthia says.

They undertook a renovation of the circa-1860 brick home, demolishing tacked-on additions to make room for an extension which included a bedroom, bathroom, dining room, mudroom for coats and boots, and a sitting room that looks out on to the vines at the rear of the property.

They repurposed an ugly water tank by constructing a deck on top, with an open rotunda-style roof designed to complement the view. It’s now an elegant and well-used feature of the grounds — the perfect spot for drinks, dining, and entertaining.

The pool house is adorned with an Egyptian chandelier and has blinds that can be drawn in winter, enclosing the space so the fire can be lit and enjoyed out of the weather. The heated infinity pool is situated with a sublime view, borrowed from the neighbouring property of vineyards.

“The pool is amazing because down the deep end there is a seat, where you can sit with a glass of wine and you look over the vineyard, which is a borrowed landscape because we don’t own it. That’s why we put the pool there, because of the vineyard.

“You sit and watch the kangaroos as they come in and eat the grass in the rows of vines. There are kookaburras and magpies, and it’s just an amazing view. There are so many koalas up here as well; we see them a lot.”

The grounds have been extensively upgraded over the years, with new roads, a portico, a pebbled forecourt and stone walling throughout the property.

When it was constructed in the 1860s, the stone would have been carted through the Adelaide Hills to the secluded site at the end of Richardson Road. Today, well over a century later, Cynthia says the property stands in perfect physical condition with no cracks or salt damp. The same goes for the home’s underground cellars.

“Just imagine getting that stone up from the plains through the Hills, in the middle of nowhere at the time, and then actually building a house that has lasted more than a century.”

The grounds are serene and typical of the Adelaide Hills, with an elm tree that is more than 80 years old, some original black locust (Robinia) trees from which Cynthia has replanted shoots, and a mature walnut that attracts black cockatoos.

Cynthia’s father owned racehorses and she has ridden since she was a youngster, even winning at a national amateur level. “I’m not a professional rider, but I’m still doing it and loving it.”

The couple built the flood-lit, full-size equestrian arena, an immaculate stable complex, a tack room and hot and cold wash bay.

“The arena’s an amazing place to train, the horses love it. It’s very quiet and sheltered and green, it’s lovely.”

Inside the home, the large ornate windows provide a garden view from every room, while lofty ceilings further the sense of openness and space. The French provincial-style kitchen features granite benchtops and an integrated dishwasher, with lime-washed floorboards.

Cynthia is a bowerbird, collecting an array of furnishings, rugs and artwork on her travels. She previously owned Grace & Grandeur Homewares in Aldgate, and her eye for interior design is evident throughout the home.

The land is fenced into five paddocks which can be used for horses, sheep, or alpacas. There are two dams, a bore and large rainwater tanks.

During the years when Paul and Cynthia’s children were growing up, the property was a giant playground for dirt biking, fishing in the dam, building tree houses and practising hitting golf balls at targets in the paddock.

The property is less than a 10-minute drive from Stirling, and within walking distance to Uraidla.

“We’re city people with country hearts and this is the best of both worlds. I can be down at Burnside shopping up a storm in 20 minutes if I get the urge.”

The sale is being handled by Arabella Hooper and Josh Biggs of Harris Real Estate.