Countless fist-sized holes stud the western and southern sides of a foundation pit -- about 10 meters deep and as large as a football field -- at a construction site, 300 meters south of the intersection between Zhengxin Road and Xiangyun Road in Xinzheng City, Henan Province. Tens of thousands of swallows build their nests at the transversal surfaces of the construction site of a residential building. [Photo/Chinanews.com]