Discreet yet stylish, this hotel is the centerpiece of so many must-dos it's easy to forget about the elegant rooms. Downstairs is Gordon Ramsay's Boxwood Café, while Harrods, Harvey Nichols, and Hyde Park are neighbors. By day, the fashionista crowd arrives for the signature Prêt à Porte afternoon tea in the Caramel Room: nibble Liz Hurley-designed bikini biscuits and cakes inspired by the latest catwalk collections (Missoni striped madeleines with banana and vanilla bavaroise; or Zac Posen dark purple macaroons with chocolate and passion fruit ganache) served on Paul Smith bone china. After dark, the David Collins-designed Blue Bar attracts a trendy crowd with its Balearic Islands soundtrack. Don't miss the top-floor swimming pool (one of only two in London); it perches above Hyde Park with a roof that slides open in good weather. Still, don't neglect an overnight stay: rooms combine marble baths with traditional French wallpaper and the occasional four-poster bed.
Insider Tip: For a pretty pound, a hotel chauffeur will collect you at the airport in an E class Mercedes ($190 each way).
Room to Book: Request one with a park view.