It's safe to say that Cardiff could have looked very, very different if these wacky developments had gone ahead.
We could be hailing a driverless taxi from our mobiles, betting big money in a super casino or even staying in Wales' tallest hotel.
But for their own reasons, none of these weird and wonderful planning ideas ever went ahead.
The hot air balloon that would have hovered over Cardiff Bay
In 2009 developers wanted to hover a 400ft hot air balloon over Cardiff Bay to offer 20-mile views across the capital, Severn estuary and the Brecon Beacons.
The proposal for the Cardiff Bay Hiflyer came from Oswestry-based Lindstrand Aero Platforms, run by Swedish adventurer Per Lindstrand.
Speaking at the time, Mr Lindstrand said: “The location in Cardiff Bay is very good and there is no other way of seeing the place from high up. It would be Cardiff’s version of the London Eye.”
As well as the Cardiff Bay blimp, the developer also wanted to install a second balloon, the Skyflyer, to the south side of Roath Basin.
Both plans received fierce opposition but by 2010 both ideas were given the green light by Cardiff Council.
However, work on the two balloons never materialised.
Cardiff's super casino
Cardiff's bid to become home to a Las Vegas-style regional super casino was officially launched in 2006 when the UK Government asked cities to bid for either the single super casino licence or one of large eight casino licences.
The casino would have likely formed part of the Cardiff International Sports Village in Cardiff Bay and would have incorporated a 220-metre viewing tower with panoramic views of south Wales and the Bristol Channel.
The ambitious plans came under fire from gambling bodies that claimed super casinos - with million-pound slot machines - would create more problem gamblers, but cities were keen to bid as the project would help to fund major regeneration projects.
However, Welsh capital was unsuccessful in both bids and then the government scrapped the legislation that allowed the casinos and the plans were shelved altogether.
The world-class wakeboard and waterski park
Cardiff was set to get its very own “world-class” wakeboard and water-ski park in 2013 after plans were given the green light.
The proposal from Cardiff Bay Wakeboarding to install a 735m cable-tow waterski system at East Bute Dock, off Atlantic Wharf in Butetown, caused months of controversy with hundreds of residents lodging concerns about noise and the impact it would have on traffic.
But despite concerns, Cardiff Bay Wakeboard was given permission operate on a five-year trial. However, according to Cardiff Bay Wakeboard, the land they proposed to use was sold on to another developer.
In 2017, the company was still looking for a suitable site.
The huge Welsh projects that never got off the ground
Cardiff Bay’s New York skyline
It’s safe to say that Cardiff Bay could look completely different.
Billed as Cardiff's New York skyline, the 2,400-flat Bay Pointe development would have given Wales a new 41-storey tallest building and two other skyscrapers.
There was even talk of musical fountains like those seen in Las Vegas.
The half-a-billion-pound investment was given planning permission in 2008, with police warning developers they have to safeguard the largest tower - which would have stood 127 metres high - against terror threats with bollards, steel walls and crash-proof barriers.
But the scheme fell apart during the credit crunch and many of the plans for the area had to be redrawn.
Wales’ tallest hotel
Work on Cardiff Bay’s £23m Bayscape development began in 2016 and last year the first residents moved into one of the 115 apartments overlooking Cardiff Marina and the River Ely.
The development also includes a waterside bar and restaurant, office units, a public realm with landscape architecture and new land facilities for Cardiff Marina.
However, perhaps the biggest and most ambitious part of the development were the plans for a 200-room hotel, serviced apartments, 103 exclusive residences, 10 niche commercial units to include three bars and three restaurants, one of which would be a 24th-floor skybar.
But developers went back to the drawing board and plans for the hotel were scrapped. Instead, developers hope to build apartments, commercial units, a concierge and a business lounge.
Driverless taxis
Driverless cars are a hot topic - while they used to be the sort of thing you’d see in science fiction films, they could soon become a reality.
But fifteen years ago, Cardiff council had serious plans to adopt an Urban Light Transport (ULTra) taxi network as a transport link between Cardiff Bay and the City Centre.
The city would have been the first to adopt such an innovative transport system.
ULTra even built a one-kilometre test track in Viking Place in Roath Docks, which is still used today to test the company’s automated vehicles.
But the city was refused two applications for grants to trial the technology.
Since then, two pods have been installed at Heathrow airport and developers hope the pods will eventually be used in a “smart city network” where driverless pods are hailed by smartphones in a similar way to Uber.
So it is possible that plans to bring them to Cardiff could one day become a reality.
Walk of fame
Welsh talent could have been celebrated with a Hollywood-style Walk of Fame when Plaid Cymru announced it was exploring plans to create Cardiff’s very own.
The first 30 stars to be honoured were expected to be decided through a public vote and it would have run from Roald Dahl Plass outside the Millenium Centre down to the waterfront in Cardiff Bay.
The likes of Tom Jones, and Charlotte Church and rugby legends Gareth Edwards and Neil Jenkins were expected to feature.
But plans were put on hold in 2007 following rows over funding.
