Over the years, there have been many ambitious plans for the London skyline, which, if they'd gone ahead, would have resulted in a vastly different skyline.
Move over Big Ben and The Shard, some of the capital's most ambitious building projects were never constructed.
Bringing together some of the most incredible plans, from a Victorian-era glass and iron skyscaper, to an enormous pyramid on Trafalgar Square, we list some of the most incredible.
1. Central London Monorail.
In the late 1960s, bus use in London was declining, as people preferred to use their own cars instead, which caused serious congestion. As a result of this, the Central London Monorail was suggested, which would have seen four loops built above London, allowing carriages to zip above people's heads.
The project was originally supported by the Conservatives, before being abandoned after a year, reports the Evening Standard.
2. Westminster City Airport.
In 1934, plans were drawn up for a central London airport above the River Thames to provide a closer business and tourism link. Designs published by Popular Science Monthly show that a runway would have stretched from Lambeth Bridge to the Houses of Parliament.
According to the project specifications, the airport would have been tall enough to accommodate the 'tallest masts of ships' and have enough length to land a single propeller aircraft.
3. Trafalgar Square Pyramid.
In 1815, plans were drawn up for a 300ft pyramid to stand in the centre of Trafalgar Square to commemorate the Battle of Trafalgar and the Battle of the Nile. It would have been taller than St Paul's cathedral.
4. The Carlton Hotel.
The Carlon Hotel was one of the world's most luxury establishments, but unfortunately during the Second World War the bombing it suffered was so severe, it was forced to close and its remains were eventually ripped down in 1957.
The building that now stands in its place is the High Commission of New Zealand, an overseas post of the New Zealand Ministry of Foreign Affairs and Trade.
5. The Victorian Skyscraper.
At the end of the Great Exhibition in Hyde Park in 1851, numerous plans were put forwards for what to do with its immense iron and glass structure. Charles Bruton suggested creating an enormous 1,000ft skyscraper with the remains, but investors opted to re-enact the original Crystal Palace in South London instead.