An excellent expression of China's imperial spirit, the Summer Palace (Yíhé Yuán, 颐和园) should be explored at leisure, even if it means setting aside a full day just to wander around soaking up the atmosphere. That said, if you're short on time, even a few hours exploring the halls, courtyards, pavilions, temples and wooded hillsides of this opulent lakeside retreat should prove a highlight of your Beijing visit.
Today's Summer Palace, or "Garden of Nurtured Harmony," owes a lot to late-imperial historical circumstance: its predecessors, including the Old Summer Palace, were destroyed by marauding Anglo-French forces, first in 1860 (Second Opium War), and then again in 1900 (Boxer Rebellion). The Empress Dowager Cixi, while presiding over the downfall of imperial China, made certain that its final years wouldn't go without a Summer Palace and poured resources—including silver earmarked for upgrading the Chinese navy—into rebuilding the ravaged pleasure grounds, completing the restoration in 1902, a scant decade before the ultimate fall of the Qing. Though she failed to keep China together, she did a bang-up job on restoring the imperial getaway.
Originally known as the "Garden of Clear Ripples," the site was established in 1750 by the Emperor Qianlong. Kunming Lake (Kūnmíng Hú, 昆明湖) was enlarged and shaped in imitation of West Lake (Xi Hu) in Hangzhou and Longevity Hill (Wànshòu Shān, 万寿山) was enlarged using earth excavated from the new lake bed. The gardens survived the two Anglo-French attacks, and the burned and looted buildings were rebuilt and expanded upon after both. Today, the Summer Palace grounds are the largest preserved imperial-era garden in China, occupying some 117 hectares (290 acres), and a UNESCO World Heritage Site. Once inside, a host of sights await exploration, from the Duobao Glazed Pagoda (Duōbǎo Tǎ, 多宝塔) atop Longevity Hill, to the painting-lined Long Corridor (Cháng Láng, 长廊), to the lake's Marble Boat (Shí Fǎng, 石舫) and temple-dotted South Lake Island (Nánhú Dǎo, 南湖岛), reached by the elegant Seventeen Arch Bridge (Shíqīkǒng Qiáo, 十七孔桥).