What is the largest man made structure in the wor ld?

Fresh Kills , the rubbish dump on staten island, New York. Opened in 1948 and became the one of the largest human projects of all time. The site is 12 square km (4.6 miles) and at its peak was 25 meters (80 feet) taller then the Statue of Liberty. It weighed 13000 tons and was closed in march 2001, it has been flattened and turned into parkland and a wildlife facility.