2. Hyde Park: London, $225 Million
With an estimated value of $225 million, the Hyde Park penthouse ranks second on our list of 10 most expensive penthouses. This magnificent London apartment spreads over 17,000 square feet with floor to ceiling windows and balconies overlooking Harrods department store and Hyde Park. It also comes with five bedrooms, two wine cellars, a wine tasting area, cinema, 21-meter pool, and a Panic Room. If you are a book lover, you should enjoy the library, study rooms, and a private study area. The Hyde Park penthouse is guarded round the clock by SAS-trained guards.