Chhatrapati Shivaji Terminus, Mumbai —
Not only is the Chhatrapati Shivaji Terminus in Mumbai the busiest train station in India, it's also a UNESCO World Heritage Site. The immense facility -- featuring a mixture of gothic turrets, stone domes and pointed arches -- serves as a terminal for long distance trains and suburban railway services. It was also featured in the 2008 hit movie, Slumdog Millionaire.