Beihai Park (Beihai Gongyuan)
Before 1911, when the Qing dynasty ended, this park was attached to the Forbidden City. Built in the 10th century, it is one of the most lavish and important Chinese gardens. The landscaping references geological features from all over China. If you miss these subtleties, you'll still enjoy a day wandering among the lakes of water lilies, marvelling at the architecture and watching the calligraphers create their fleetingly beautiful poems in water on the flagstones.
The garden is actually mostly lake (Beihai means 'Northern Sea'), but there's plenty to look at on land. There's an immense white jade Buddha from Myanmar (bearing a war wound in the arm from the Boxer Rebellion days), a green jade jar dating from the thirteenth century, the 9 Dragon Wall with its cavorting dragons and clouds, a white stupa decorated with the sun and the moon, and countless other temples and pavilions.