Mumbai is not only India's largest city, it's also one of the largest cities in the world, both in size and population. Nearly 20 million are crammed into an area of a little more than 4,000 square km (1,600 square miles)—that's about 5,000 people per square km (11,000 people per square mile). On a peninsula jutting out of the western coast of India and facing the Arabian Sea, in the state of Maharashtra, Mumbai is roughly equidistant from the three other main Indian cities of New Delhi, Kolkata, and Chennai.
- Colaba. The tip of Mumbai's peninsula is one of the oldest parts of the city, home to the majestic Taj Mahal Palace Hotel, the Gateway of India, and the Colaba Causeway, the city's main commercial drag.
- Fort and Marine Drive. From the winding lanes of quaint Kala Ghoda (a tiny enclave within the Fort District) to the long promenade of Marine Drive, this neighborhood provides a good wander, and the best seafood in town.
- Malabar Hill and Nearby. Mumbai's richest neighborhood also houses some of the city's most important holy sites.
- Central Mumbai. A bit of a no-man’s-land when it comes to sightseeing, the densely populated center of the city does have a number of choice dining and lodging options.
- CST and Nearby. In the shadow of Mumbai's massive Victorian train station, this is where you'll find the city's best street food and the biggest, busiest bazaars.
- Elephanta Island. Just a short ferry ride from South Mumbai lie the ancient caves of Elephanta: a historic getaway from the ultramodern city.
- Juhu, Bandra, and the Western Suburbs. The neighborhoods along the northwestern side of the peninsula and on the suburban train line are growing fast. Juhu, probably the northernmost suburb tourists are likely to visit, offers a number of nice hotels, and Juhu Beach—great for a sunset walk. Bandra is home to Bollywood's studios, and where most of India's biggest celebrities live. Other suburbs have restaurants that make a visit worthwhile.
- Aurangabad and the Caves. Aurangabad, about 400 km (250 miles) east of Mumbai, is a base for exploring the astounding cave temples of Ellora and Ajanta.