Even the ceremonial centre is assembled haphazardly.And here is the magic - this labyrinth is not a prison It constantly dissolves into fantasy and escape. All is surprise, fascination and diversion:Tony Parsons, writer and presenterThe greatest thing about London is being able to live within walking distance of a bookshop, a Vietnamese restaurant and Highbury football ground, the home of football. There is no way of standing outside it because it is not a place but a medium which only ever reveals parts of its parts. Its space, like that of the universe, is curved; but, as with the universe, you can only be inside London. This is the nearest London ever gets to purity of form, and for the uninitiated this is London at its most terrifying.London doesn't have straight lines. Outside the endlessly redeveloped core, in the late 19th-/ early 20th- century suburbia, the mysterious labyrinth exists in almost pure form: miles and miles of chimney-potted gables. The place is an aggregate of one-offs, and we scramble about as best we can.London has no edge.

It flows on and on, in every direction, and most of it is flat, so that it's rare to gain a perspective beyond the next twisted street. Culturally, socially and physically, it grows in and out of itself, and the suburbs, when you reach them, are not young.Other cities are ringed with suburbs of modern residential towers: London suburbs have mediaeval hearts with Tudor and 17th-century skeletons, 16th-century muscle, 19th-century flesh, 20th-century plastic surgery. It's a city of houses, and, because an Englishman's home is his castle, every house wants to be different and have a door directly onto the street. The result is bizarre conjunctions and chemical combinations - no uniformity at all Nothing coherent lasts in London for long.

The one chance for a rational plan - Wren's, after the Great Fire - never took off, and London has continued to burgeon as a random heaven and hell. Where the hell...?London is the first and archetypal city as blind giant: the anonymous and unappeasable maw. It is the most playful and eccentric mess, a phantasmagoria without visual or tribal cohesion.Not for nothing is it the capital of the pragmatic English, who always eschew the big picture. I was born here, went to school here, and have lived half my life here; then yesterday someone said they lived in Lower Clapton. London is always the great sea, a seething stew: formless, limitless, ever-changing, unknowable.

Now it's very cosmopolitan; it's grown and changed and become much more fun, but it's also a place where you see a lot of street-drinking and many more damaged people than beforeYou can go up the Empire State Building, look down on the circumference of Manhattan, and say: "Yes, I could have this town in my hand." You may walk all round Paris in a day and feel: "Yes, this town could be mine." But such feelings can never arise in London, a city it is hardly possible to grasp, let alone possess. When I go to Portobello Road, I experience a 50-year leap: I lived there as a child when it was a Cockney London Irish ghetto. There weren't many people homeless on the street, but Ian Dury was the one person I remember as representing the spirit of a hopeful London night person - like most Londoners, he's obdurate and carries on I think of Portobello Road. Rabbi Julia Neuberger, born and bred in Hampstead, currently lives in Clapham I love the view across the Thames from Vauxhall or Westminster Bridge, looking down towards the City and Canary Wharf. I like the contrast between St Paul's Cathedral - the old - and the bulk of Canary Wharf - the new; the sense that London is still growing but has kept its traditions John Bird, editor, `The Big Issue' When I was a kid, I slept rough, using London streets as a getaway both from my parents and the police. I just think that if you're going to dump your fundamentals, dump your ideology and disown your history, you're going off into the desert without a map." His brow twitched "Like Mark bloody Thatcher".