London's Colosseum stood in Regent's Park from 1824 to 1875.

Regent's Park Colosseum was designed by architect Descimus Burton, consisting of a colonnaded portico attached to a domed rotunda. Inside the domed rotunda, a 360° panorama of mid-nineteenth century London was depicted from the viewpoint of St Paul's Cathedral, as witnessed by artist Thomas Horner when repairing St Paul's dome. Artist E. T. Paris took Horner's designs and, along with a select team, painted the entire dome is just over one year.
This image was used by 'The Penny Magazine' to depict London's Colosseum. The article mocks how the building is not architecturally resemblant of Rome's Colosseum, and from further research I discovered that Descimus Burton had based the building around the Pantheon in Rome instead of what its name suggests.

This is the Pantheon in Rome today, now being used as a Church. However, in many ways, London's Colosseum was a combination of both Rome's Pantheon (architecturally) and Colosseum as an amphitheatre. As a staged image of London's nineteenth-century panorama, the Colosseum represented classical ideals within the unforgiving environment of industrialised Britain.

The Colosseum was advertised as a more accessible way of seeing London for all visitors and its vastly increasing populous. The Penny Magazine also describes how the ascension to St Paul's cupola was treacherous, and the modern contraptions in the Colosseum (as pictured) were a much easier and 'safer' way to to 'view London'.

However, this accessibility was greatly limited by the fact that not only was there an entrance fee for the Colosseum, but also Regent's Park was reserved for mainly upper- and middle-class visitors (and residents), thus cutting out a large majority of Londoners.

The 'glittering' city in the 'smokeless air' is a quote from Wordsworth used in The Penny Magazine article to describe how Thomas Horner admired the capital city at four o'clock in the morning when repairing St Paul's cupola. This view was then used by E. T. Paris for the exact replica inside the outer-wall.

This was not necessarily a 'fake' view of London, but a London not quite awake, without the smoke, steam or smog of the working hours. Importantly, this was a view that most Londoners would never witness.

Perhaps too much emphasis is placed on how 'fake' the Colosseum was, with an unrealistic panorama inside a neo-classical hybrid structure of bricks coated in cement. The Colosseum was, instead, a great feat of technical and artistic engineering, with innovative platforms for viewing. In a time before air travel, skyscrapers or geolocational maps and before air pollution became a political matter, London's Colosseum was perhaps a very British amphitheatre for viewing London, one not exposed to the weather. As authentic, one could argue, as open-air lawn tennis at Wimbledon, with the electronic cover sealed shut.

London needed to be seen as the new Rome; the capital city of the British Empire. The view from the Colosseum presented a falsified Imperial city (from the neo-classical exterior to the rose-tinted painting).

Just to put the Colosseum in context, slavery was abolished in the British Empire in 1833, so the city needed to further impose upon the world that it was truly the colonial nucleus of power, civilisation and money. Such a metropolis should be easy to view in its entirety at any time of the day, or year, by its inhabitants and visitors. Evidently, the lifespan of the Colosseum was congruous to Britain's dominance as the world's imperial superpower.

Additionally, The Penny Magazine article talks about London (and England) as the centre of civilisation as well as capitalism and all the benefits it reaps, yet also in 1833 the Factory Acts were passed through parliament that limited, but did not eradicate, child labour.

There may be no exact examples of places in London that you can visit to experience a false panorama of London (quite the opposite in fact that there are many more viewing platforms in London today).

However, in many cases a highly edited composition of London landmarks or geographically incorrect skyline are preferable to the true sprawling city.

E.g. this London 2012 advertisement, most news channel or chat show studios back drops, introductions to films or television series, or general pamphlets that focus around
London (e.g. TFL travel-card brochures).

Regent's Park Colosseum was more about London itself being 'seen to be seen' rather than the architectural, artistic or innovative