Cormorants are used by some fishermen on the rivers to catch fish for them. China's natural environment has been adversely affected by human intervention in a number of ways. Deforestation has gone on for many years. In 1978 steps were taken to protect the environment. There is now a programme of tree planting and a national conservation organization looks at the consequences for the environment of using pesticides and chemicals.
Many ancient tombs survive intact and are visited by tourists.
The Great Wall of China, built to keep out potential invaders, is probably the country's most famous structure and was started over two and a half thousand years ago. It was expanded in the mid fourteenth century and is more than 5,000 km long. At the present time, the government is trying to limit the rate of population increase by persuading families to restrict themselves to one child for each married couple. Over ninety per cent of the population are Han Chinese which also includes the Hakka people. Altogether there are fifty-six nationalities in China.