Hebei Province, 233km (146 miles) NE of Beijing
If you can do only one overnight side trip from Beijing, make it Chengde -- the summer camp of the Qing emperors. Here, in a walled enclosure containing numerous palaces, pavilions, and pagodas as well as a vast hunting park, the emperors escaped Beijing's blazing summer temperatures, entertained delegations from home and abroad, and practiced the mounted military skills which had originally gained them their empire. The design of the resort, built between 1703 and 1794, was shaped by its varied diplomatic functions. Some buildings are plain and undecorated to show visiting tribesmen that the emperors had not lost touch with their roots or been too softened by luxury; others were copies of some of China's most famous and elegant buildings; and some were giant edifices with hints of minority architecture, intended both to show the emperor's sympathy for the traditions of tributary and border-dwelling peoples, and to overawe their emissaries.
In 1794 Britain's Lord Macartney arrived on a mission from George III, and not finding the Qianlong emperor at home in Beijing, followed him up to Chengde. He was impressed by the resort's vast scale, and was shown around by people who anticipated modern guides' hyperbole by telling him that the gilded bronze roof tiles of the Potala Temple were of solid gold.
The Jiaqing emperor died here in 1820, as did the Xianfeng emperor in 1861, having signed the "unequal" treaties which marked the close of the Second Opium War. The place came to be viewed as unlucky, and was already decaying by the fall of the Qing in 1911. But the Mountain Retreat for Escaping the Heat, along with the remaining Eight Outer Temples around its perimeter, still form one of the greatest concentrations of ancient buildings in China. It's an 18th-century version of a "Splendid China" theme park (as seen in Florida and Shenzhen), but with oversize buildings rather than the miniatures offered there.
Ordinary Beijingers now follow imperial tradition by flocking here to escape the baking summer heat. You can hurry around the main sights by spending a night here, but you might want to spend 2.