the great wall of china the longest man-made structure 6,300 kilometres long dates from the ming dynasty eastern end--western end--shanhaiguan jiayuguan hong kong international airport the bi
ggest civil engineering project of all time took six years to build & cost us$20 billion the three gorges dam the largest hydro-electric dam in the world more than 1.5 kilometres wide across reservoir--more than 500 kilometres long do you know what the three gorges are? qutang gorge is famous for its high cliffs. wu gorge is known for its beautiful scenery. xiling gorge is a dangerous gorge, and it has many ancient relics. but some of the beautiful scenery disappeared. why? walls of stone to hold back clouds & rain till a smooth lake rises in the narrow gorges. ?ü???÷?-??±?, ?????×?????ê, ????????????