"London." a London Travel Page by mwe

London does not have a "City Centre" or "Downtown Core" in the way that other cities do. The exact centre of London must be the theatre district around Shaftesbury Avenue & Leicester Square.
When Londoners talk of "The City" they don't mean London generally, or central London: they mean "The square mile" financial district of east-central London. "The city" is the original city of London & apart from financial institutions it is where the Tower of London, Tower Bridge & St Paul's Cathedral are.
The City of London has its own police force, separate from "The Met" who police the majority of London!
There is also a "City of Westminster" which is the western part of central London: where Parliament, Buckingham Palace & the main shopping & entertainment area (aka "The West End") are.
The "West End" was originally a posh residential area (still is in places), but became a shopping & entertainment area from Victorian Times & consists of areas like Soho, Mayfair, Belgravia, Knightsbridge, Kensington & Chelsea.
Docklands, to the east of The City, has been redeveloped since the 1970s & now consists mainly of office blocks, housing developments, hotels, etc.. Quite a lot of UK national newspapers have relocated from Fleet Street to Docklands since the 1970s.
From the afore-mentioned centre of London, Greater London spreads out across roughly a 15-mile radius: making it compact compared to North American cities.
London's premier airport, Heathrow, is on the westernmost extremity of Greater London, 15 miles from the centre by road, rail or Underground.

In the 1920s & 1930s most of London's suburbs were built, generally outside the London County Council area, mainly in Middlesex county.
In the 1960s, the Greater London Council (GLC) was created as the political boundaries of London were updated to include the entire built-up area of London. Middlesex was abolished, except as a postal county.

However, in the 1980s, the GLC was abolished by the right-wing Conservative government of Margaret Thatcher. Thatcher objected to the GLC's left-wing leader, Ken Livingstone, giving money & support to Irish republican groups, left-wing governments in places like Nicaragua & his friendships with people like Colonel Gadaffi, Fidel Castro, marxist groups & left-wing union leaders.

Under the left-of-centre Blair government since 1997, the GLC has effectively been revived as the London Regional Assembly, with Ken Livingstone as Mayor of London.

Londoners are sometimes referred to as "Cockneys": however, the definition of a Cockney is someone born within the sound of Bow Bells (Bow is an inner suburb in east London). People in other parts of London often object to being referred to as "Cockneys".

...Similarly, people in the suburbs of Greater London often object to being called Londoners & they refer to their suburbs as "villages" (which they were up to Edwardian times).

Cockneys use Rhyming Slang, which apparently came about to stop posh people in the west-end listening to their conversations. Established examples of Rhyming Slang includes "North & South" ("Nawf & Sarf" in a London accent) for mouth. However, Rhyming Slang is always being updated, for example club DJ Pete Tong's name has found its way into Rhyming Slang to mean "wrong" ("It's all gorn <gone> Pete Tong"). Another complication is to abbreviate Rhyming Slang: for example Cockneys say "loaf" to mean "head", because the full Rhyming Slang for "head" is "Loaf of bread".