The #JubileeLine extension recently won the superlative accolade of Millennium Building of the Year by the Royal Fine Art Commission Trust. In addition, four stations were specially commended - Westminster, Southwark, Canary Wharf and North Greenwich.
The Wallace Collection is simply the most beautiful space to be in central London. A 18th century townhouse for a family that seems to have collected just about eveything, it is now a free museum with a lovely atrium in the center. If you get there when it opens you can explore these beautiful rooms almost entirely alone. -> Tube Stop: Bond Street (Central and Jubilee lines)