Helensburgh's most famous house has been added to an exclusive list of the world's most notable  20th century properties.

The Hill House is the only property in Scotland to have been added to iconichouses.org, alongside 187 homes around the world that get a mention for their architectural significance.

But It's not just a site to learn more about design gems from famous names such as Frank Lloyd Wright or, in the Hill House's case, Charles Rennie Mackintosh.

The website, which is based in the Netherlands, says it "focuses on advocacy, preservation, house museum management and cooperation".

The non-profit network also links up experts - something Hill House bosses are excited about as they continue to explore the best options to restore and preserve the National Trust of Scotland site.

Speaking earlier this year to the Advertiser, project manager Liz Davidson said members of Iconic Houses could sit on various technical forums, such as for walls, which are continuing to dry out at Hill House underneath its protective frame, or 'Box', after decades of water ingress.

READ MORE: Helensburgh's Hill House welcomes addition of Mackintosh design

"There will be buildings with similar issues we want to speak to," she said as 20th century homes face climate change threats.

Anne Foy, of Destination Helensburgh, told the Advertiser: "Destination Helensburgh is delighted to hear that The Hill House has joined other architecturally significant 20th century buildings such as Gaudí's La Pedrera, Eames House and Frank Lloyd Wright's Fallingwater as part of Iconichouses.org. 

"Having such a special and internationally recognised building in Helensburgh draws visitors to the town, and benefits the whole community.

"We look forward to hearing more about this exciting collaboration."

The property is listed as an "architect house" and is the only one in Scotland to make the list.

But it isn't the only Mackintosh property to get a mention, with 78 Derngate in Northampton, the only house that Mackintosh designed in England, also earning a place.

The description states: "The Hill House is considered to be Charles Rennie Mackintosh's domestic masterpiece.

"Commissioned by Glasgow book published Walter Blackie, up-and-coming architect Charles Rennie Mackintosh (1868-1928) and his wife Margaret Mackintosh Macdonald (1864-1933), a well-established artist and interior designer, worked collaboratively to create almost everything you see at the property, from the building itself to the furniture and textiles.

"The external render of the property has not proved watertight. The Hill House has embarked on a 10-year conservation programme, allowing continued public access to the house.

"Stage one opened to visitors in 2019, with a protect steel frame structure covering in chainmail mesh, featuring walkways around and over the top of the house."

Under "highlights", the website states: "The house features Mackintosh and Macdonald's best domestic interior designs fusing art nouveau, Japonisme and hints of art deco in stencilling, stained glass, ceramics, carpentry and textiles set against the contrasting, darkly atmospheric and brilliantly lit interiors that were the hallmark of their designs.

"Externally the largest temporary steel shelter and gangway in Europe allows visitors the opportunity to walk around and over the house to appreciate the sculptural qualities and architecture of the house which draws on Mackintosh's strong belief to develop a new modern vernacular architecture with its roots in Scottish tradition but embracing new technology and materials."