Along with the bronze pigs, Rundle Mall is defined by Bert Flugelman’s larger than life steel sculpture 'Spheres'. The Hindmarsh Building Society donated it in 1977 to the City of Adelaide to mark the society’s centenary. Originally dubbed 'On Further Reflection' in the years since then it has become an Adelaide icon and is fondly known as the “Malls Balls”. It remains perhaps Adelaide's most successful example of public artwork, so seamlessly integrated into people's perception of a public place that the notion of 'abstract artwork' is rarely mentioned.

Vienna-born Flugelman migrated to Australia at a young age, studying at the National Art School in Sydney and exhibiting internationally before taking up a post lecturer and later Head of Sculpture at the South Australian School of Art between 1972 and 1983. Of all his works, Spheres is the most prominent reminder of his decade in Adelaide.

To create this massive piece Flugelman worked with Adelaide firm Brister & Co. In the early 1970s the techniques required to fashion stainless steel into the forms envisioned by Flugelman had only been mastered by a few local workshops. The family run firm collaborated on other Flugelman sculptures including the steel Tetrahedra found outside the Festival Centre, but for this project, Flugelman presented Brister with a new challenge: a small model of two balls coated in silver paper impaled on a stick, to be replicated on much larger scale. The spheres were created in halves, before being welded together and panel beated.

The image of the two connected spheres graces T-shirts, key rings and posters of Adelaide, sometimes with the phrase “Adelaide’s Got Balls”. The sculpture is a popular meeting spot in the Mall. It has been the focal point of several events, from flash mob dances to protests.

There was some controversy in January 2013 when it was suggested the sculpture be moved as part of the Rundle Mall upgrade. The artist himself said “If I can stop it I will because like many people, I'm used to it there. It becomes a landmark … People become used to saying ‘I’ll meet you at the balls’. This is part of the history of the city.”

Fortunately, the Malls Balls were not moved and are still the meeting place for many Adelaide shoppers.