After Foster + Partners' design for the Tulip tower was recently rejected by the UK government, we round up 10 other high-profile building projects that were never actually built.
Mexico City airport by Foster + Partners
The Tulip is not the first time Foster + Partners has seen its design efforts go unrealised. Construction on this airport for Mexico City was half-complete when the project was cancelled in October 2018.
The cancellation came after a public referendum on the airport was called by Andrés Manuel López Obrador, who was at that time Mexico's president-elect, and resulted in a majority vote against it.
López Obrador had made cancelling the project a key part of his election campaign over concerns about the $13.3 billion expected cost, as well as alleged corruption and environmental worries.
Find out more about the cancelled Mexico City airport ›
For a while, Copenhagen-based BIG's vision for a skyscraper made from stacked glass boxes that decrease in size as the building ascends seemed to be the strong forerunner for the Two World Trade Center.
But after a protracted back-and-forth, the developer of the World Trade Center site in New York opted last year for a skyscraper by Foster + Partners over BIG's design.
A tower that is similar in spirit could still grace the Big Apple skyline, however. Last month, Adjaye Associates launched proposals for a building that resembles an upside-down version of the BIG World Trade Center tower.
Find out more about BIG's Two World Trade Center design ›
New Tamayo Museum by Rojkind Arquitectos and BIG
BIG partnered with local studio Rojkind Arquitectos on the proposal for this art centre in Mexico.
The pair won a competition to design the New Tamayo Museum overlooking Mexico City back in 2009, but more than a decade later, it remains unbuilt.
Had it gone ahead, the museum would have resembled a cross jutting out of the hillside via a cantilever, with a large viewing platform on its flat roof.
Find out more about the New Tamayo Museum ›
Tokyo 2020 Olympic stadium by Zaha Hadid Architects
After winning the initial design competition for Tokyo's Olympic Stadium in 2012, Zaha Hadid Architects (ZHA)'s proposal met with heavy criticism from high-profile Japanese architects over its size and cost. Public support was also shaky, with the stadium's shape compared to a crash helmet and a potty.
In July 2015, Japanese prime minister Shinzo Abe scrapped ZHA's design and the studio was unable to enter the reopened competition, having failed to secure a construction company.
The Japan National Stadium eventually built for the Olympics was designed by Kengo Kuma and Associates.
Find out more about ZHA's Tokyo Olympic stadium design ›
Stamford Bridge by Herzog & de Meuron
Swiss studio Herzog & de Meuron, working alongside London architecture firm Lifschutz Davidson Sandilands, revealed its design for a major overhaul of Chelsea FC's Stamford Bridge stadium in 2015.
The proposal to enclose the existing stadium in a net of 264 brick piers gained planning permission in 2017 but was mothballed a year later because of funding difficulties and amid ongoing visa problems for the west London football club's Russian owner, Roman Abramovich.
Planning consent ran out in March 2020, meaning Herzog & de Meuron's vision for the stadium will not see the light of day.
Find out more about Herzog & de Meuron's Chelsea FC stadium design ›
Mansion House Square by Mies van der Rohe
This amber-glass office tower in the City of London, designed by modernist Ludwig Mies van der Rohe, was in development for 20 years but never actually built.
Mies van der Rohe finished the design just a few weeks before his death in 1969, and famous British architect Richard Rogers described the plans as "the culmination of a master architect's life work".
Prince Charles, however, was less enamoured of what he called a "giant glass stump", and a long campaign against the tower by the royal helped ensure its ultimate rejection following a 1984 public inquiry.
The building was the subject of an exhibition held at the Royal Institute of British Architects in 2017.
Find out more about Mansion House Square ›
Italian architect Carlo Ratti unveiled plans for a mile-high observation tower almost twice the height of the Burj Khalifa in 2016.
Though The Mile was not planned for a specific location, Ratti's studio claimed that numerous cities had expressed interest in building it.
Nearly six years on there have been few updates about the plant-covered tower, which was designed to have a park at its top and was intended to provide an ecosystem for hundreds of different species.
Find out more about The Mile ›
RAK Convention and Exhibition Centre by OMA
In 2007, architecture firm OMA unveiled plans for a huge convention centre to be part of a new city at Ras Al Khaimah in the United Arab Emirates (UAE).
However, the Death Star-like structure never became reality.
OMA also designed a structure plan for RAK, which envisioned a "mix of functions, flexibility, and a strategic reserve" for the area, which has a projected population growth to 600,000 inhabitants by 2025.
Find out more about the RAK Convention and Exhibition Centre ›
Jebel al Jais Mountain Resort by OMA
The exhibition centre was not the only ambitious UAE project floated by OMA in 2007 that was ultimately never constructed.
The studio also produced a proposal for a tourist village on a mountainside in Ras Al Khaimah, which would have seen an inhabited dam, an inhabited bridge and a vertical village all built into a cliff.
Find out more about the Jebel al Jais Mountain Resort ›
Garden Bridge by Thomas Heatherwick
The Garden Bridge, designed for London by Thomas Heatherwick, has become an infamous recent example of an abortive major building project.
Championed by now-UK prime minister Boris Johnson, who was mayor of London when it was announced in 2013, the plant-covered bridge was ditched in 2017.
That came after an inquiry found that the cost of building the Garden Bridge had risen from the original estimate of £60 million to more than £200 million, leading to Johnson's successor in City Hall, Sadiq Khan, withdrawing his support.
Find out more about the Garden Bridge ›