Dongtan is a city located in South Korea. It has many shops and restaurants. There are also 4 skyscrapers ranging between 70 to 80 floors in which people live. They are collectively called Metapolis and they contain a shopping mall. Dongtan also has an underground subway called the SRT(Supreme railways train) that goes from suseo station to jije station. The subway is 52.3km long and it is the third longest in the world. It is also has the longest underground tunnel for a subway that goes at a speed of 300km.