There's a version of London for whichever mood strikes you, and most visitors end up doing all of them in a single week. Watch the scarlet-coated guardsmen at Buckingham Palace, then queue politely for the crown jewels at the Tower of London; do it in a chauffeured black cab if walking feels like hard work. History buffs will want Westminster Abbey and a climb to St Paul's Whispering Gallery, while the more energetic among you can explore the Square Mile before hunting street art through Shoreditch. Greenwich rewards a slower afternoon: the Cutty Sark, the Royal Observatory's meridian line (one foot in each hemisphere, camera ready), and a cruise back up the Thames with a glass of something cold. Follow 007 through Mayfair, the Beatles across Abbey Road, or simply settle into Borough Market and a proper afternoon tea. London never really switches off.
The King's Guard hand over duty on the forecourt of Buckingham Palace, bearskins on, band playing, the whole thing done to the minute. It runs on set mornings rather than daily for much of the year, so check the date before you go. Get there early, or you'll be watching the back of someone's head.

A private licensed cab and a driver who has passed the Knowledge, which is the closest thing London has to a walking encyclopedia with wheels. You'll roll past Big Ben, St Paul's, and Tower Bridge with commentary and no jostling. Good in the rain, which is a real consideration here.

Namibrand, Namibia