This Himalayan city, the capital of Tibet, sits at an elevation of 12,000 ft/3,660 m. A good introduction to Lhasa is the Barkhor Bazaar, where you could spend hours just watching people. In the midst of the bazaar is the fabulous Jokhang, holiest of Tibetan Buddhist temples. It's filled by a steady stream of pilgrims who have gone to pay respect to their gods, represented in the temple by an incredible array of devotional art. Be sure to wander around the second floor, and don't be shy about sticking your head into rooms where craftsmen are creating additional gods.
Visible from almost any point in Lhasa is the Potala Palace. Once the Dalai Lama's winter residence (he has been in exile in India since 1959), it's one of the world's architectural wonders—the entire building, consisting of thousands of rooms, was created without the use of a single nail. Each of the 70 or so rooms that are open to the public has an atmosphere all its own. (Most are lit only by wicks stuck in yak butter.) The light reflects eerily off the gods, murals, and gold-plated figures. Allow four hours to explore this magnificent building; as with other great museums, it's better not to try to see everything in one day.
Other sights around Lhasa include Sera and Drepung monasteries and the summer palace. The famed sky burials (where corpses are flayed, cut up and fed to the vultures) of Sera have caused increasingly aggressive confrontations between foreign tourists taking photos and domden (undertakers) trying to carry out their religious duties. You really need a strong stomach to observe this, and most people don't bother with it. Lhasa can be seen in two days, but because of the altitude, allow three or four days. (You'll want to do nothing but rest on the first full day.) 800 mi/1,300 km west of Chengdu and 375 mi/600 km northeast of Kathmandu, Nepal.