The old city of Delhi is the nerve center of the city in many ways. It's the arrival and departure point for many travelers going to and fro by plane and train. The old city is also the center of the city for backpackers and the hostels are concentrated in some of the most interesting and vibrant streets citywide. The train station that joins places like Rajasthan and Kolkata is located in Old Delhi, and you can access many of the city's enclaves through its subway stops from here. It's a chaotic place, full of social inequality. You can see the rough lives of the people here. It's dusty and dirty, but also a fascinating place that's full of life and experiences for the traveler who's willing to live a thousand adventures.