Delhi is the best place to experience all that brings people to India: history, culture, food, spirituality, madness, mystery. Spend a day amid its lived-in splendor, and you’ll realize why so many battles have been fought over it. Here are the extremes that make India so compelling. Old Delhi's Mughul glory, Central Delhi's European grandeur, West Delhi's Punjabi opulence, and South Delhi's bars, boutiques, and massive houses—all come together with the poor, the pollution, and overpopulation.

Modern Delhi has its foundation on a city base that has been around for centuries. Various monuments lie scattered across the region, revealing the numerous empires that have invaded Delhi and made it their home. Of these, the Mughals and British have left the deepest mark.

The city has grown exponentially over the years and continues to do so to accommodate the expanding population, currently estimated at more than 16 million, within a little less than 1,554 square km (600 square miles). It's part of the larger National Capital Region (NCR), which includes neighboring state suburbs like Ghaziabad, Faridabad, Noida, Greater Noida (all across the border in Uttar Pradesh), and Gurgaon (in Haryana). The latter is known in particular for its call centers and gleaming malls, which feed the consumer craze of India’s rapidly expanding middle class.

In Delhi the different versions of modern India all coexist, and its contradictions quickly become abundantly clear to visitors. Newly minted junior executives ride in chauffeured, air-conditioned comfort as scores of children beg and hawk magazines in the streets.