Parliament House designers Mitchell/Giurgola and Thorp believed the interior of the building was as important as the exterior. The furniture had to reflect Australia and Australians and be "eminently worthy of being part of the nation's heritage", even down to the door handles.

With that in mind, Parliament House is conducting guided behind-the-scenes tours of its furniture and art collections, from towering murals (one of which Gough Whitlam scrawled his initials onto, at the request of the artist) to the 93 humble timber benches dotted around the place (all made from a rare private timber collection). There is a rug by fashion designer Jenny Kee. Artist Arthur Boyd created a large landscape painting Untitled (Shoalhaven Landscape), which formed the basis for the design of the Great Hall tapestry. The painting hangs in a corner of Parliament House; Boyd an amazing 83 when he was commissioned to do the work. Most things have a story to tell.

Department of Parliamentary Services visitor experience director Cris Kennedy said the art and furniture tours were tailor-made for the Enlighten Festival, when a light was shone, literally, on the Parliamentary Triangle.

"Enlighten is about more than light, it's a celebration of Canberra," he said. "It's a time when everyone comes out to enjoy this sense of community."

Visitors will also be able to see some of the less public pieces in the Parliament House art collection, which numbers some 7000 works. Mr Kennedy said about $3 million had been invested in the artworks over the last 32 years. The collection was now valued at $120 million. Howard Arkley's Theatrical Facade was a particularly canny purchase, bought for $10,000 and now worth $500,000.

The artworks are regularly rotated around the building, the "more robust" in the places that catch the strong, western sun; the less so on the other side of the building. Only one artwork doesn't move, mainly to orientate staff and visitors around the building, the gold mosaic kangaroo, My Bloody Oath by Danie Mellor.

Official portraits reflect the personality of the subject. Mr Kennedy especially likes the one of Joan Child, the first female speaker of the House of Representatives who worked in both the old and new Parliament House. She wanted her portrait to reflect some of her old workplace, so there is a push-button telephone on her desk and the mottled greens of Old Parliament House interiors in the background.

Mr Kennedy promised a "deeper dive" into the collections. Take, for example, the architects' design for the Member's Desk which "intentionally has no drawers for storage of papers, based on the principle that an executive or manager at that level should not be a person concerned with storage and retrieval".

(And the painting with the "GW" scrawled in it? Take a very close look at River Odyssey in the Members' Hall by Michael Ramsden and Graham Oldroyd. The artists were big fans of Gough and asked him to add his initials while they were completing the work.)