Concierge.com's insider take:
The only truly new neighborhood in London is Canary Wharf, a complex of offices and shopping malls centered around the city's tallest building, César Pelli's One Canada Square. There are few clues that this used to be a blighted area, part of the Isle of Dogs (a peninsula and former dockyards)—Stanley Kubrick's Full Metal Jacket was filmed here after the demolition, before the building began. Take the Jubilee Line to Canary Wharf station (a modern cathedral-like structure designed by Sir Norman Foster), and wander down to the river. Get a good view of this futuristic neighborhood as you leave aboard the elevated monorail, the Docklands Light Rail, which winds its way between the buildings back to central London (www.tfl.gov.uk/dlr).