Regarded as the largest imperial garden in China, Beijing's Summer Palace is in fact a park-styled royal retreat, extending out over 10 square miles in northwest suburban Beijing. Once a summer resort for emperors, this 290-acre partk-palace is still a retreat for visitors, who can take a rest here or wander around old pavilions, buildings, temples, bridges and the huge lake - Kunming Lake. Summer Palace is mainly comprised of Longevity Hill (Washoushan) and Kunming Lake. Much of the park is covered by Kunming Lake. With masterly design and artistic architecture integrating the highlight of Chinese garden arts, the Summer Palace has earned a title of "Royal Garden Museum". It is a royal garden most completely preserved with richest landscapes and large compact buildings. The Summer Palace was listed as the world cultural heritage in 1998.