My favourite city is Seoul.Seoul is the capital of South Korea and is located on the Han River in the country's northwest. The city is situated about 50 km (~30 mi) south of the North Korean border， also known as the de-militarized zone (DMZ). Seoul is a city with ancient history， the area of Seoul appears in history as early as 18 BCE， when the kingdom of Baekje founded its capital， Wiryeseong， in what is now southeastern Seoul. Modern Seoul descends from a city called Namgyeong， built during the Goryeo era， which then became the capital of the Joseon dynasty in 1394. Seoul has been the capital of successive Korean nations ever since.Designated the status of a Special City， Seoul is administered directly by the national government.
With over ten million people， Seoul is South Korea's largest city and one of the largest cities in the world by population. Covering an area of only 605 square kilometers， smaller than New York City or Tokyo， it is one of the world's most densely populated major cities.
The Seoul National Capital Area， which includes the major port city of Incheon， has almost 23 million inhabitants making it the second most populous metropolitan area in the world， after Greater Tokyo. Almost half of South Korea's entire population lives in the Seoul National Capital Area， and nearly one quarter in Seoul itself， making it the country's political， cultural， and economic center， as well as a center for international business. The rapid economic， social and technological development of the city has played a key role in South Korea's development， and has been referred to as the "Miracle on the Han River".
Seoul hosts more than three million registered vehicles and widespread traffic congestion is common. In recent years， the metropolitan government has undertaken extensive clean up of the city's air and water pollution. The revival of Cheonggyecheon， a stream that flows through Seoul city center， was a recent major urban beautification project.