the marble boat, also known as the boat of purity and ease (the summer palace in beijing, china)

summer palace beijing china unesco world heritage site imperial garden yuan harmony cultivation area square construction year location haidian district northwest center park pavilions season history emperor qianglong ming dynasty destroyed 1860 opium war legends extravagances excesses late autumn best times enjoy view entire boat ride lake winter frozen navigation marble also known purity ease shapound ashy facurren aeng lakeside pavilion located grounds