Cornwall and the South West have more than 20 homes open for the Invitation to View programme

Every home has a talking point. For Sarah Marsh, it happens to be a magical, disappearing wall. This incredible feature was discovered by accident when Sarah and her family moved into Coombe Trenchard, an Edwardian manor house just over the border in west Devon.

“When we came here we had absolutely no knowledge of this wall until we found a series of clues,” says Sarah, who has lived in the house in Lewtrenchard since 2007.

“We discovered this concealed door and inside were these pilasters (a section of column attached to a wall) which were an exact match to others present on the walls elsewhere in the hall.”

After more detective work, Sarah and a few willing volunteers discovered an elaborate sash’ system which allows the wall to be raised and then sunk back into the floorboards.

The unique contraption - thought to be the only one of its kind in the country – was designed to make the hallway bigger or smaller, depending on the number of guests one had to entertain.

Sarah is kindly showing me a few of Coombe Trenchard’s beautiful features as part of Invitation to View – a scheme set up to allow people to go behind the closed doors of some of the country’s most spectacular privately owned properties.

All you have to do is buy a ticket and visit your house of choice after making an appointment on the available dates.Around 20 houses are signed up to the not-for-profit co-operative in the South West, the idea being that visitors can get a behind-the-scenes look with the best tour guide possible – the homeowner.

“It’s a wonderful idea,” says Sarah. “Every building has a story to tell and who better to tell it than the owner. You get all these little anecdotes along the way.”

Sarah says the scheme has helped her to understand more about her home and its history.“I’ve learnt so much through taking people around on the tours. We’ve had people here who were the daughters of the original craftsmen and others who have given insights on what particular things were for. It helps to piece it all together.”

Invitation to View started life in Suffolk in 1998 with 14 houses and gradually spread nationwide, taking in the Westcountry just over three years ago.

People can book as individuals or get a group of friends together to enjoy a guided tour as part of a holiday or weekend day-trip.

Some of the houses included in Invitation to View:

Bosvathick, near Falmouth, Cornwall: The county house has been owned by one family since the 1760s. The little-know gardens have camellias, azaleas and rhododendrons.Lukesland, near Ivybridge, Devon: This Victorian gothic house is celebrating its 150th anniversary. The gardens include Britain’s largest magnolia.Shilstone, near Modbury, Devon: This is now a restored Georgian house, although evidence shows it was once the site of a Domesday manor.

Its landscape includes the only known 17th century water theatre in Britain.

Cothelstone Manor, near Taunton, Somerset: This property has a Grade II* listed gazebo, built for the wedding of Sir John Stawell in 1619.

To book online, visit invitationtoview.co.uk or call 01206 573948.