Deep in the National Library in Canberra, this high security storage space contains some of the nation's rarest, most valuable and fragile items.

Fairfax Media was granted rare access to 'the vault' this week, accompanied by a small gaggle of enthralled staff who, themselves, don't often get to see inside.

It was in this very room that curators recently uncovered Australia's first pound note - dating back to 1913 and now worth at least $1.5 million - tucked inside a folder, where it had laid undiscovered for nearly 80 years.

Once past the doors – one of which is several inches thick - the vault looks nothing like the glittering treasure trove one would expect.

Lit by fluorescent lights, measuring just three metres by 10 metres, and kept at a constant, chilly 17 degrees, the room's beige blandness belies the priceless treasures stored neatly in non-descript boxes and files.

But, in a collection that represents a nation, one historian's priceless medieval document might pale into significance for the literary junkie once she lays eyes on the beret once worn by the writer Patrick White, with white hairs still clinging to its inner rim.

And the strongroom isn't the library's only repository of the weird and wonderful; scattered throughout the building are collections of varying levels of fragility and security, conserved as part of the psyche of the nation.

One collection that has many people titillated, but only from a distance, is the nation's pornography stash, kept strictly off limits to the public.

It's a necessary by-product of the library's legal deposit requirements, under which it is legally obligated to collect "all printed material about Australia or Australians".

Surprisingly or not, this collection is not popular among those staff tasked with cataloguing it.

Other items have arrived in the collection in a more roundabout way: Billy Hughes' false teeth, for example, were nestled amid his personal papers, and help give a more complete picture of the person Australia's seventh Prime Minister had been.

Equally ghoulish, but not nearly so well-provenanced, is a slightly grubby, leather-bound book of poems in the rare books collection, that just happens to be bound in human skin.

Other collections are complex and poignant in a way that other nations would not recognise, like the letters of Lindy Chamberlain, clocking in at nearly 200 boxes and counting.

Among them are Azaria Chamberlain's hospital tags, alongside thousands of letters sent to her mother by well-wishers.

And still more items have, at least this week, a pleasing historical synchronicity.

Exhibitions curator Nat Williams, a long-time staff member enjoying a rare jaunt along the shelves, is particularly taken by a teapot once owned by the famed naturalist Sir Joseph Banks.

It was given to him – in his old and deteriorating state – as a get-well gift by none other than Queen Charlotte.

Mr Williams, who curates the library's popular Treasures Gallery, said he had often called up items from the strongroom for eventual display.

But even after more than 16 years on the job, he said he was constantly surprised by the items he uncovered while searching for other things.

"I can't say it's on a daily basis, but it's certainly weekly that I find something and think, my god, I wouldn't have thought that we'd have that here," he said.

"I think people assume that libraries are going to be about books and journals and maps, but they don't think about objects that are connected to people, like Henry Lawson's death cast of his hand, or Patrick White's beret, glasses and beanie."

Mr Williams said the fact the pound note had been undiscovered for so long was understandable, given the scale of the collection, and the fact that many things were uncovered by accident.

For example, a Tiffany medal commissioned by the American Geographic Society and presented to the explorer Thomas Griffith Taylor, who survived the unsuccessful Captain Scott polar expedition in 1910, was apparently found hidden inside a sock in a box of papers.

"It's these things that connect people," Mr Williams said.

"It's an endless process. We'll never run out and we're always acquiring more interesting stuff as well."