Tonight is a convenient time for a taste of classic Peking Opera (86-10-6351-8284; tickets from $25)—though the taste is an acquired one—at the Huguang Theater, a former guild hall dating from 1807. The show starts at 7:30 p.m. and you'll be out by 9—or at intermission (but first visit the open-during-intermission-or-upon-request opera museum attached to the theater).

You'll want to wake up early tomorrow, so forgo a sit-down dinner in favor of some quick and authentic food at the Donghuamen Night Market. The many yummy noodle, dumpling, and veggie snacks should be safe as long as they are boiled or steamed while you watch (Donghuamen Dajie; dishes, $3–$8). Two blocks away is the Beijing 2008 Olympic Flagship Store (Wangfujing St.), in case you'd like to make a souvenir run.

Day 3 (Monday): The Great Wall and the Summer Palace
The Great Wall—the world's longest, built 2,200 years ago to protect China from invading armies—tends to lose some of its grandeur when crawling with baseball-capped tourists. Leave your hotel at 7 a.m., however, and you can avoid Monday morning rush hour and ascend the wall before the hordes arrive. There are six sections of the Great Wall accessible to the public—all in various states of decay or restoration—that you must choose among. If you're an avid hiker who has always dreamed of climbing the Wild Wall, you'll want to drive three hours to Jinshanling or Simatai and do the seven-mile hike between them with an experienced guide (since parts have been reduced to rubble). If you're not that rugged or time is a factor, your best bet is the Mutianyu section of the wall, only 90 minutes from town. The watchtowers are in good shape, the cable car is safe, the vistas are beautiful (if it's a clear day), and although there are plenty of vendors selling tourist schlock, at least they're kept off the wall itself. If you leave your hotel at 7 a.m., you will have three hours at Mutianyu—ample time to walk for a mile in each direction before lunch.

En route back to Beijing, stop for a couple of hours at the Summer Palace (86-10-6288-1144; en.summerpalace-china.com), the imperial retreat where, from the eighteenth century until the start of the twentieth, the emperor and his household escaped Beijing's summertime heat. It's a vast park filled with temples, pavilions, gardens, a huge lake, and the world's longest covered walkway, decorated with 8,000 paintings. It's best to visit in the midafternoon, because it can be a mob scene in the morning. Walk the Long Corridor, climb Longevity Hill to the hilltop temple if visibility is good, take a dragon boat ride on Kunming Lake, and hit Suzhou Street—a re-creation of the garden city of Suzhou in the Qing dynasty, with shops, walkways, and the ambience of a canal town that was built for the Qing rulers.