Delhi

In 1739, a Persian invader named Nadir Shah marched into Delhi and left with so much treasure it took thousands of elephants, camels, and horses to haul it away. He took the jewel-covered Peacock Throne and the Koh-i-Noor diamond, which now sits in the British Crown Jewels.

The loot was so vast that he canceled all taxes in Persia for three years.

Delhi has been conquered, looted, and rebuilt more times than almost any city on Earth. It's often called the city of seven cities, because at least seven separate capitals rose and fell on roughly the same ground.

The oldest, Lal Kot, dates to around 1052. Its centerpiece still stands: the Qutub Minar, a 72.5-meter tower begun in 1192 and the tallest brick minaret in the world.

Nearby sits the second city, Siri, built by Sultan Alauddin Khalji around 1303. According to legend, its foundations hold the severed heads of 8,000 Mongol invaders he defeated. The name Siri comes from "sir," the word for head.

The Mughals made Delhi their crown jewel. In the 1640s, Emperor Shah Jahan, who also built the Taj Mahal, constructed a brand-new walled city called Shahjahanabad, now known as Old Delhi.

At its heart he raised the Red Fort, a sandstone palace that served as the Mughal seat of power for 200 years. India's prime minister still gives the Independence Day speech from its walls every August.

The British took over in 1857 and built their own city. Architect Edwin Lutyens designed New Delhi with wide avenues and grand government buildings, and it was inaugurated in 1931.

Inside the Qutub complex, find the Iron Pillar, a column more than 1,500 years old that has somehow never rusted. Tour the Red Fort and the enormous Jama Masjid, which holds 25,000 worshippers in its courtyard. Visit Humayun's Tomb, the 1570 garden tomb that became the blueprint for the Taj Mahal.

Take a rickshaw through the packed lanes of Chandni Chowk. Eat a stuffed paratha in Paranthe Wali Gali, crispy spiced chaat, and a coil of hot jalebi. Order butter chicken, the dish said to have been invented right here in Delhi.