Project Manager of Collections Eddie Butler-Bowdon with a collection of portraits of Moomba Kings and Queens.

Collection manager Eddie Butler-Bowden with the heritage-listed collection of portraits of Moomba kings and queens. Photo: Justin McManus

A 25-YEAR-OLD bottle of Spumante, a road sign covered in stickers, doe-eyed portraits of Moomba princesses and posters that spruik screenings of films about venereal disease.

At first glance these eclectic items may not strike you as ''heritage'', but the City of Melbourne insists they are, and has developed a plan to protect the city's history as it comes under increasing pressure from growth.

As well as historic buildings, gardens and monuments, Melbourne's heritage includes things like the street art on Hosier Lane, the archaeology of the city, retro advertising signs and sites of public protest, the strategy says.

''The City of Melbourne's heritage is facing the challenge of urban growth inherent in a modern city … [which] will place pressure on the existing built fabric of the city,'' it says.

A nondescript building on Little Bourke Street holds the council's vast trove of heritage items, including a series of 1930s posters that ''cordially'' invite the public - women and boys under 16 were banned - to watch films about the ''human pitfalls'' of venereal disease, followed by an organ recital (no pun intended).

On another shelf sits a framed copy of a ''freedom of the city'' certificate inscribed to Nelson Rolihlahla Mandela, a gift for the South African leader when he addressed the council in Melbourne upon his release from jail, the first time - anywhere in the world - that he was invited to speak to a democratically elected forum.

His invitation to speak had been debated long and furiously by councillors at the time, with some not in favour of marking his visit, says collection manager Eddie Butler-Bowden.

The 20-year-old archive has recently increased its collection of street art, including a two-way street sign from Hosier Lane - which is a big drawcard for tourists - which is covered in stickers made by street artists.

''The best years of street art [at Hosier Lane] may have already passed,'' Mr Butler-Bowden said, ''All art movements have their moment of flowering.''

Mr Butler-Bowden said the council's role was to be a custodian of the city's heritage but this responsibility was shared by governments, community groups and residents.

And the commemorative bottle of Moomba Spumante? That was picked up from the ground after the parade and somehow made its way into the city's collection. ''Some people say that no one drank it because it was undrinkable,'' said one of the curators.