一、地理位置与古园林史北京大学校园位于北京城西北郊海淀镇北侧。海淀一带正是北京小平原的尽头,西山山麓的起界,是一处出闹市而又未入山林的郑野地。这一带是永定河洪积扇下缘,又是摇摆不定的永定河之古河道。有丰富的地下水出露, I. Geographical location and history of ancient gardens Peking University campus is located on the north side of Haidian town in the northwest suburbs of Beijing. Haidian District is the end of the small plain of Beijing, and the starting point of the Xishan Mountain is a Zhengye field where there is a bustling city that has not yet entered the mountains. This zone is the lower edge of the Yongding River alluvial fan, and it is also the ancient river course of the undulating Yongding River. Extensive groundwater exposure,