<Tr> <Td_colspan="2"> The Great Wall of China at Jinshanling </Td> </Tr> <Tr> <Td_colspan="2"> Map of all the wall constructions </Td> </Tr> <Tr> <Td_colspan="2"> Wikimedia © OpenStreetMap </Td> </Tr> <Tr> <Th_colspan="2"> General information </Th> </Tr>

How long did it take the chinese to build the great wall of china