Laid out by British architect Edwin Lutyens, the Indian capital is a striking modern metropolis. A gracious contrast to Old Delhi's winding streets, the grand avenues and stately buildings of New Delhi are rich with history and culture, from Gandhi's Delhi home (and the site of his assassination) to the tomb of Humayun, a complex of Mughal buildings reminiscent of the Taj Mahal. Chaotic traffic is best left to the locals. Negotiate a good price for taxis or travel on the new Delhi Metro.

Srinigar is a modern waterworld, dominated by Dal Lake and its twisting waterways, tree-lined Nagin Lake, and the Jhelum River. Engulf yourself in local culture by embracing your sea legs and renting one of the wooden boats called shikaras for a daytime or twilight cruise. On land, stroll through the terraced hillsides of the 400-year-old Mughal Gardens, created by Emperor Jehangir for his wife, and shop for indigenous crafts like hand-woven silks and embroidered shawls.

Known as both the "Garden City" and "The Silicon Valley of India," Bangalore (officially "Bengaluru") is a techie’s paradise, boasting the highest concentration of IT companies in the country. When you’re done geeking out, there are plenty of gardens, museums, natural features, palaces and temples to fill your dance card. Visit Vidhana Soudha, Cubbon Park and the Ulsoor Lake of Bangalore, well known for its beautiful locales and boating facilities. Bangalore is also a major centre of Indian classical music and dance, and of vivid, cutting-edge nightlife.

The people of Tamil Nadu consider providing food to others a service to humanity. Thus the service in the state capital, Chennai, is first-rate. Treat your senses to some of the richest South Indian flavours in traditional dishes like sambar, rasam, fish curry or kootu. And don't forget to have a cup of full-bodied Tamil coffee, enhanced with chicory—no visit is complete without it.

Though most simply pass through Coimbatore on their way west, tarriers are rewarded with a lively street-food scene, city museums, and parks. Add in easy access to the hilltop temples surrounding the industrial city, and you have a raw gem waiting to be discovered.

Thrissur is regarded as the cultural capital of Kerala, a beautiful coastal region of southwest India with a history deeply rooted in the spice trade. For an exercise in absolute serenity, schedule an overnight houseboat tour of the local backwaters. If you’re lucky enough to visit during the temple festival of Pooram, you’ll experience lively music performances, fireworks, shadow puppet shows and processionals of beautifully adorned elephants.

Kodaikanal has an endangered animal called the grizzled giant squirrel. To us, that alone is reason to book a trip ("grizzled giant squirrel" might be the best animal name ever). Perched on the woodsy southern crest of the Palani Hills, nearly 7,000 feet above sea level, this popular lakeside resort town is a magnet for nature lovers. Wander the peaceful slopes, keeping an eye out for birds, exotic flowers and, of course, grizzled giant squirrels.