One hundred kilometres off the central Queensland coast lies an island paradise famous in yachting circles but largely hidden from the public.

Shrouded with rumours of buried treasure, Middle Percy south-east of Mackay is a rare gem where mariners can come ashore freely and wander through memorabilia of bygone days.

It's known for its tradition of hospitality and beauty, but with no ferry or airport, it's reserved for private vessels crewed by those with a sense of adventure.

A rustic A-frame shack built in the 1970s by a passionate former resident, Andy Martin, is the heart of the island and meeting place for visitors moored in the protected bay.

Thousands of pieces of memorabilia have been left by travellers at an A-frame structure. (ABC News: Ellie Willcox)

Its walls are littered with random and unique mementos left by travellers from around the globe.

Signs, buoys, art, flags, caps, clothing and trinkets are strung up thoughtfully throughout the hub.

Andy Martin's cousin, Cate Radclyffe, described the building as a "labour of love".

The shack was built by former resident, Andy Martin, in the 1970s. (ABC News: Ellie Willcox)

"Thousands of visitors leave their memorabilia there, and they love to see it every time they come back,"

she said.

"They love to add to it, and people will be finding plaques that their parents had left or even their grandparents had left.

"It's a wonderful bit of living history."

Thousands of mementos have been left by visitors. (ABC News: Ellie Willcox)

Ms Radclyffe first visited her cousin, who was leaseholder at the time, in 1984 and "fell in love" with the island.

"It's just so special, I suppose because it's quiet, you don't have the hurly burly of life around you," she said.

"There's no commercial enterprises like on the other islands, be it Keppel or the Whitsundays."

Middle Percy Island is untouched by commercialism. (ABC News: Ellie Willcox)

Tradition of hospitality