21. One of the quirkiest buildings in the city, 1 Poultry features a boat-shaped facade and clock face. The postmodern structure was conceived by the architect James Stirling.
20. The ArcelorMittal Orbit Tower certainly makes a statement in London's Queen Elizabeth Olympic Park. Much of the winding structure, which was designed by sculptor Anish Kapoor with engineer Cecil Balmond, is made out of recycled steel.
19. Unilever's London headquarters is housed in 100 Victoria Embankment, a Grade II-listed building originally designed by the architect John James Burnet. The interior — which was more recently transformed by architecture firm KPF — is super modern, with interconnected bridges and platforms creating a multi-level open space.
18. Designed by Nicholas Hawksmoor and completed in 1729, Christ Church in Spitalfields is a beautiful example of English Baroque architecture.
17. If Trellick Tower in Kensal Green looks like a block of council flats, that's because it was a block of council flats. The Grade II-listed building — which was completed by the Hungarian architect Erno Goldfinger in 1972 — is now hailed as a masterpiece of Brutalist architecture.
16. The history of Leadenhall Market goes back to the 14th century. Wrought iron and glass were added to the structure in an 1881 renovation by the architect Sir Horace Jones, giving the market its famous Victorian style.
15. Alexandra Palace in north London has suffered from two fires in its history since it was built in 1873, but its facade today retains its grand Victorian style.
14. The Serpentine Sackler Gallery in Kensington Gardens is comprised of two parts — the Magazine, a former gunpowder store that was built in 1805, and a modern curved structure designed by Zaha Hadid. The 21st-century addition to the gallery creates a stark contrast between past and present architectural styles.
13. Designed by Horace Walpole in the 18th century, Strawberry Hill House in Twickenham is known for its striking Georgian Gothic revival style.
12. City Hall's tilted structure — which looks as though it's leaning away from the Thames — makes it one of the most unique buildings in the capital.
11. The futuristic-looking Lloyd's Building was designed by Richard Rogers, with a bold, shapely design fashioned out of concrete, stainless steel, and glass.
10. Formerly home to the Carreras Cigarette Factory, Greater London House in Mornington Crescent is one of London's coolest Art Deco buildings. Designed in an Egyptian Revival style, the large cat sculptures at the entrance and cats' faces adorned along the side make this office building unique.
9. Home to the University of London's library, Senate House is an impressive Art Deco building in Bloomsbury that was designed by Charles Holden in the 1930s.
8. The new Switch Building at London's Tate Modern was designed in an eye-catching flame-like shape by Herzog and de Meuron.
7. Leadenhall Building — or the Cheesegrater — is another structure designed by Richard Rogers. Its wedge-like shape, angled at 10 degrees, gives the skyscraper character, while offering exquisite views of nearby landmarks like St. Paul's Cathedral and 30 St. Mary Axe (the Gherkin) to those inside.
6. Designed by the British architects Chamberlain, Powell and Bon, London's Barbican Centre is known for its symmetrical sharp and curved lines. The Brutalist style buildings comprise the largest performing arts centre in Europe, as well as housing.
5. King's Cross Station's stunning transformation by John McAslan and Partners includes a giant web-like structure that spreads throughout the train terminal.
4. Watch tourists' jaws drop as they look up in the Great Court — designed by Norman Foster — at the British Museum in London.
3. With its triangular shape and sharp jagged edge, the M by Montcalm building is a dramatic addition to east London's architecture.
2. Designed by the architect Colin St John Wilson, London's Grade I-listed British Library is home to the world's largest collection of books — and a stunning, sleek interior made up of wavy staircases and sharp lines.
1. Among London's most beautiful buildings, the St. Pancras Renaissance Hotel and King's Cross Clocktower stand out on Euston Road thanks to their striking Gothic Revival facade, designed by the architect George Gilbert Scott.
