Samuel Johnson had it right.
"Sir, if you wish to have a just notion of the magnitude of this city, you must not be satisfied with seeing its great streets and squares, but must survey the innumerable little lanes and courts. It is not in the showy evolutions of buildings, but in the multiplicity of human habitations which are crowded together, that the wonderful immensity of London consists."
London is not just the tourist crowds along the West End, nor the millionaire mansions of Kensington. London's wonder is in its hidden places, from the stretch of rusting railyards past Wembley out East along the river to Barking, as the city gives way to its surroundings. It's walking from Greenwich to London Bridge at 4am, following the slow curve around the Isle of Dogs, to get a warm breakfast at Borough Market as the sun rises over the city. It's the pulse and beat of the city that gets into your veins, and the endless teeming life of the place, from tower blocks to tube lines to twenty-four hour stores.