The Marble Players, Sheen, Plane Spotters and the Ali Babas - to those not in the know these are merely cryptic phrases.
But all are public artworks freely on show in Sheffield, a mere handful of the hundreds of pieces commissioned over the years to enhance new spaces, commemorate events and champion culture.
While some, such as the stainless steel Cutting Edge water feature outside the railway station, and Colin Rose's Rain - the nine metal spheres between the Peace Gardens and Winter Garden - have woven themselves into the fabric of the city, others have faded into obscurity.
The Marble Players, for instance, is on Attercliffe Common, and depicts a boy and girl in the middle of a game of marbles, carved in Derbyshire gritstone by artist Vega Bermejo. The piece was never formally unveiled on its completion in 1992, and the children's glass marbles have been broken and removed.
The Plane Spotters, meanwhile, has had a chequered history. Commissioned by the council in the 1990s for the ill-fated Sheffield City Airport, Mike Disley's limestone sculpture of a man and woman was kept in a quarry in Doncaster for several years and now sits, chipped and damaged, on part of the Transpennine Trail near Catley Road, Darnall.
"There are artworks all over our area, usually funded by EU or Lottery funding, and there doesn't seem to be any aftercare or even pointing out where they are and why they are there," says Joy Bullivant, of the Time Walk Project, which promotes heritage trails in Sheffield.
The Eye of the Needle, a piece by David Nash from 1992, is one such example of a 'neglected' sculpture, Joy says. The oak column, with a split for the needle's 'eye', was installed on the Five Weirs Walk along the River Don, but the timber has deteriorated and trees are blocking it from view.
"I think public art is wonderful, and it can brighten up a dull landscape, but it needs to be documented so people know about it, surely."
Art historian Darcy White, a principal lecturer in visual culture at Sheffield Hallam University, is one of the few people to have compiled a comprehensive list of the city's public artworks. Along with her late colleague Elizabeth Norman, she wrote an illustrated book, Public Sculpture of Sheffield and South Yorkshire, for a series published by Liverpool University Press.
The book involved researching 750 pieces across the county before whittling them down to a manageable selection.
"Everything had to be visited and assessed for its condition, and every trace of the history had to be uncovered," says Darcy.
When commentator and historian John Holland toured Yorkshire in 1851 he expressed disappointment at the small number of sculptures he found, but Darcy's book argues that Sheffield 'ultimately acquitted itself well'. Sir Francis Chantrey created his very earliest works locally, the Town Hall has a frieze and reliefs by Frederick Pomeroy and much later the city made a significant contribution to the renaissance in public art in Britain from the 1980s onwards.
But she believes political debates around the cost of artwork have come at the expense of proper discussions about how individual pieces should look.
"It always came down to 'This city needs investment into the poor, health issues, schools, hospitals, the slum dwellings of the 18th and 19th century - we can't possibly put money into monuments and sculpture.' Even I've got some sympathy with that idea. That perpetuates all the way through the story of public art in Sheffield. If the local people thought money should be spent another way it would be very hard to get a commission off the ground."
Thirty years ago Sheffield adopted a 'per cent for art' policy, where new investors and developers were required to pay for sculpture in return for being given planning permission. "It meant they didn't necessarily have their heart in what they were doing, so some of it's successful and some isn't. We haven't been all that bold as a city in terms of what we've commissioned, and actually you haven't got to look much further afield to find slightly more interesting things. Barnsley is doing it quite well. They're aligning themselves much more with the Yorkshire Sculpture Park, and so they're much braver, I think. In a way it's been a missed opportunity."
Martin Jennings' Women of Steel sculpture, next to the City Hall in Barker's Pool, is the most high-profile work to be unveiled in Sheffield in recent years. "I'm a feminist and it's fantastic we're celebrating women's contribution. But it's a pretty safe piece of sculpture."
Darcy asks, rhetorically, where Sheffield's standout pieces are. "It's a question, isn't it. The Cutting Edge does seem to strike a chord with people. It says something about local history and culture. It is very clever. They never planned for the water to be part of it. But the feedback was that it would just get ruined by graffiti, so they came up with a solution."
Sheffield Council is trying to build support for Onwards and Upwards, the planned piece by Alex Chinneck that will replace the demolished Tinsley cooling towers beside the M1 near Meadowhall. Chinneck wants to put up a mile-long trail of 100ft red-brick chimneys along the Sheffield and Tinsley Canal, and the project has been shortlisted for up to £4 million from the Government's Northern Cultural Regeneration Fund, which will allow for extra elements such as picnic areas, an outdoor event space and a visitor centre.
A sculpture park is also taking shape at Park Hill, where a wing of the estate is to be turned into a £21 million cultural centre occupied by the S1 Artspace group.
Andrew Skelton, the authority's public art officer, says there is now a 'much more robust approach' to acknowledging and preserving works.
"We try to commission art that is integrated into the fabric of new buildings and places rather than as stand-alone sculptures," says Andrew. "This approach began very successfully with the Peace Gardens with its carved stonework, artist-designed ceramic tiles, seats and even litter bins."
Silversmith Brian Asquith produced bins, benches and bollards for the gardens that are now standard throughout the city centre. "Although different in scale, Alex Chinneck’s proposal fits with this approach. The trail is not simply an artwork but contributes to the area, helping to make it a place that people want to visit and enjoy and boosting the local economy."
In recent years the maintenance of artworks has been covered by a sum paid upfront to guarantee the lifetime costs. This cannot include full restoration, however, with the exception of Women of Steel, where a special arrangement has been made. The council keeps a number of works in storage, including Made in Sheffield, a piece by Amanda King formed from sheets of stainless steel that used to stand near the Wicker Arches, and the old Crimean War monument originally installed at Moorhead in 1863. King's work was apparently unpopular, while the monument is said to be too expensive to reinstall elsewhere.
The Eye of the Needle, meanwhile, has 'naturally degraded over the years', Andrew explains. "The sculptor’s original intention was that the work should be surrounded by birch trees that were trained in a leaning position. Unfortunately this birch woodland was not maintained."
And as for tSheen and the Ali Babas - the first is a sandstone and stainless steel grid by Mick Farrell at the top of Howard Street, dedicated to Sheffield-born comedian Marti Caine following her death in 1995, while the latter - six metre-high pieces of stone carved by Victoria Brailsford into shapes reminiscent of baskets - is on High Street.
"Public art has an important role to play in telling the story of the city and helping to create places and spaces that people enjoy and cherish," says Andrew.
Lesser-known and lost artworks:
Ingots, by Mark Firth, 2008 - Two fluted steel columns in the grounds of Endcliffe Student Village
Horse and Rider, by David Wynne, 1978 - A 12 foot high rearing horse and young male rider in Fountain Precinct, Barker's Pool
Cutlery, by Victoria Brailsford, 1998 - Six gritstone monoliths with surface carvings of cutlery, on a traffic island at the junction of Hoyle Street and Penistone Road
Mother and Two Children, by Ronald Pope, 1953 - A tiered stone structure depicting a mother, a boy and a girl outside Brook House Junior School, Beighton
The Beasts of Brincliffe, by Jason Thomson, 1999 - A carved beech sculpture showing an owl, bat, dog, fox and beetle in Chelsea Park, Nether Edge, now naturally rotted.
Marathon Gates, by Hilary Cartmel, 1990 - Sporting figures cut into steel plate, welded on to two gates at the demolished Don Valley Stadium. Now on display at Kelham Island Museum.