What was the terrain before the completion of Yuanmingyuan?

At that time, the terrain should be described by an idiom, that is, beautiful mountains and rivers and a treasure trove of geomantic omen. Please refer to:

Site selection and gardening

In the western suburbs of Beijing, there are endless Xishan Xiufeng: Yuquan Mountain, Wanshou Mountain, Wanquanzhuang, Beihai and other landforms. There are artesian springs everywhere, which converge into lakes and ponds in low-lying places. Yuquan landscape flows into Kunming Lake from west to east, becoming the largest water surface in the western suburbs. Large areas of paddy fields have been cultivated here, forming a natural scenic spot. As early as Liao Dynasty, the feudal emperors chose this place to build Yuquan Mountain Palace. In the Ming dynasty, the natural scenery here attracted more tourists, so some dignitaries occupied the countryside to build villas, and large areas of land were occupied by pieces. During the Wanli period of the Ming Dynasty, Hou Liwei, the closest relative of the Ming Dynasty, built a lot of buildings here, first of all, the Tsinghua Campus, which is known as "the first garden in Beijing" (so it is located outside the western wall of Peking University). Later, Mi led the lake to garden outside the east wall of Tsinghua campus, and managed the elegant and beautiful "spoon garden", which means "Haidian spoon". In the open countryside, pavilions and lakes and mountains complement each other and become a famous garden gathering place in the suburbs of Beijing. In the Qing dynasty, the emperor also took a fancy to the western suburbs, an excellent gardening place. Start building gardens on a large scale. (Later Yuanmingyuan) The above is based on Baidu Encyclopedia!