About Greenwich Situated on the River Thames, Maritime Greenwich is a World Heritage Site and famous for such historic landmarks as the the Royal Observatory, the home of Greenwich Mean Time and the Meridian Line, Longitude 0°, and inspirational architecture by Sir Christopher Wren at the Old Royal Naval College. So near to central London yet only 20 minutes from the city centre, Greenwich is a place of contrasts, from awe-inspiring architecture, tranquil open spaces and breathtaking views, to cosy pubs and bustling street markets. As you wander through Greenwich you will experience views and vistas that have changed little since Canaletto painted it almost three hundred years ago.