Cairo is big: just how big you'll see on the drive in from the airport, which sometimes takes so long you'll think you're driving to Aswan. And what you see on the way into town, amazingly, is only half of it—Cairo's west-bank sister city, Giza, stretches to the Pyramids, miles from Downtown. But if you are the sort of person who instinctively navigates by compass points, exploring Cairo will be a breeze because the Nile works like a giant north–south needle running through the center of the city. If not, you might find the city bewildering at first.
Taxi drivers generally know only major streets and landmarks, and often pedestrians are unsure of the name of the street they stand on—when they do know, it's as often by the old names as the postindependence ones—but they'll gladly steer you in the wrong direction in an effort to be helpful. Just go with the flow and try to think of every wrong turn as a chance for discovery.
Thankfully, too, you don't have to conquer all of Cairo to get the most out of it. Much of the city was built in the 1960s, and the new areas hold relatively little historical or cultural interest. The older districts, with the exception of Giza's pyramids, are all on the east bank and easily accessible by taxi or Metro. These districts become relatively straightforward targets for a day's exploration on foot.
Old Cairo, on the east bank a couple miles south of most of current-day Cairo, was the city's first district. Just north of it is Fustat, the site of the 7th-century Arab settlement. East of that is the Citadel. North of the Citadel is the medieval walled district of al-Qahira that gave the city its name. It is better known as Islamic Cairo. West of that is the colonial district. Known as Downtown, it is one of several—including Ma'adi, Garden City, Heliopolis, and Zamalek—laid out by Europeans in the 19th and 20th centuries. (The west-bank districts of Mohandiseen and Doqqi, by comparison, have only sprouted up since the revolution in 1952.) The most interesting sights are in the older districts; the newer ones have the highest concentrations of hotels, restaurants, and shops.