Istanbul is the crossroads of civilizations, where Europe meets Asia, and where West meets East. One of the world's most historic cities, Istanbul was once called Constantinople, named for the fourth-century Roman Emperor Constantine the Great. Over the centuries, the city has been the capital of two grand empires. The Byzantine Empire was born here in the fourth century A.D. and lasted until the 15th century, when the Ottoman Empire took over, ruling through the end of World War I. Even though Turkey isn't actually governed from Istanbul (Ankara, in the east, is the official capital), the city remains the historical, cultural, and financial center of the country.

Istanbul: A Verbal Map

Istanbul, with over 15 million people, sprawls over an enormous area on both banks of the Bosphorus Strait (Boğaziçi). The Bosphorus runs north to south (from the Black Sea to the Sea of Marmara) through the middle of Istanbul, splitting the city in half and causing it to straddle two continents: Asia and Europe. Asian Istanbul (east of the Bosphorus) is residential, while European Istanbul (west of the Bosphorus) is densely populated, containing virtually all of the city's main attractions. Two suspension bridges—the Bosphorus Bridge and the Fatih Sultan Mehmet Bridge—span the Bosphorus Strait, connecting the two halves. Public ferries also link both banks, carrying millions of people each day to and from work.
A tapering inlet of the Bosphorus, called the Golden Horn (Haliç), runs roughly east to west, slicing through the middle of European Istanbul.
South of the Golden Horn is a peninsula known as the Old Town—the 3,000-year-old historical core of the city surrounded by fragments of the original Byzantine wall. Near the tip of the Old Town peninsula is a compact and welcoming district called Sultanahmet, home to many of the city's most famous sights (Hagia Sophia, Blue Mosque, Topkapi Palace) and its highest concentration of hotels and restaurants.
North of the Golden Horn is the modern, westward-looking, European-feeling New District (called "Pera" by locals), centered on Taksim Square and bisected by the main pedestrian drag called Istiklal Caddesi (which we'll refer to as Istiklal street). The New District offers some interesting sights, good hotels and restaurants, and a 21st-century contrast to the Old Town.
Unlike many other European cities, Istanbul doesn't branch out from a main town hall or central square. In many parts of town, you may get lost if you're searching for a predictable, European-style square. (The Turkish word for "square"—meydani—actually means something more like "area.") Instead, Istanbul is a cobbled-together collection of various landmarks and patches of land, all interconnected by twisty alleys. Sightseeing this decentralized, seemingly disorganized city can be intimidating for first-time visitors. But even though the city is an enormous metropolis, the tourist's Istanbul is amazingly compact and walkable, and an impressive public-transportation network efficiently connects the major sightseeing zones.

Planning Your Time

Istanbul demands a minimum of two days, but we'd suggest at least four days to do it justice. Even with a week, you'll find yourself running out of time to tackle everything the city has to offer.

Istanbul in Two Days

On the morning of Day One, focus on the Sultanahmet district in the center of the Old Town. Take the self-guided Historic Core of Istanbul Walk to get your bearings, visiting Hagia Sophia, the Underground Cistern, and the Blue Mosque. With additional time, tour the Turkish and Islamic Arts Museum (small collection in the heart of Sultanahmet) or Topkapi Palace (time-consuming sultans' complex a short walk away).
On Day Two, follow the self-guided Old Town Back Streets Walk—including tours of the Grand Bazaar, Mosque of Suleyman the Magnificent, and Spice Market. You'll finish near the Galata Bridge, where you can end your day with the self-guided Golden Horn Walk.

Day Three

If you haven't done so already, tour Topkapi Palace and the nearby Istanbul Archaeological Museum. Or, if you're museumed out, consider Day Four's New District activities, below.

Day Four

Devote this day to the New District, following our self-guided walk (including the Pera Museum and Galata Tower). When you're finished with the walk, consider taking a taxi to Chora Church to see its sumptuous Byzantine mosaics. Or, if you'd rather stay in the New District, choose from a range of other sights: Dolmabahce Palace, Military Museum, Quincentennial Museum of Turkish Jews, or Istanbul Modern Arts Museum.

Day Five

Go to Asia. Set sail on the Bosphorus Strait, spending a full day going up to the Asian fishing village of Anadolu Kavağı, then returning to the Old Town.

Istanbul in a Week

More time gives you more options, from some of the smaller museums to quintessential Istanbul experiences such as soaking in a Turkish bath, watching Whirling Dervishes spin themselves into a trance, or lazily smoking a water pipe (nargile) filled with apple tobacco.