Griff Rhys Jones is visiting London in this episode of The Greatest Cities in the World - and he is discovering some hidden secrets above and underground of this diverse metropolis of the old world. British comedian Griff Rhys Jones visits six important metropolises of the world, including New York, London, Rome, Paris, Sydney and Hong Kong. He looks into oddities, traditions and hidden secrets, discovering what makes these cities the greatest in the world. Subscribe to see more full documentaries every week: https://bit.ly/2lneXNy TRACKS publishes unique, unexpected and untold stories from across the world every week. From "The Greatest Cities in the World with Griff Rhys Jones" Facebook: https://www.facebook.com/TRACKSTravelChannel/ Content licensed from DRG to Little Dot Studios. Any queries, please contact us at: owned-enquiries@littledotstudios.com owned-enquiries@littledotstudios.com