Seoul, officially known as the Seoul Special City, is the largest metropolis and capital of South Korea. This megacity is the largest city proper in the developed world and the Seoul Capital Area is the second largest metropolitan in the world with more than 25.6 million people, which is half of all the residents in the country. The estimated population within the city limits for 2016 is 10.29 million.
The population of Seoul in 2016 is estimated at 10.29 million, although this is just the population of the Special City, which has a density of about 17,000 people per square kilometer (45,000/square mile). The sprawling metropolitan area is much larger at 25.6 million.
Interestingly, Seoul's population density is almost twice that of New York City, four times higher than Los Angeles and eight times higher than the density of Rome.
Seoul is divided into 25 gu, or districts, which range from 10 to 47 square kilometers and populations under 140,000 to over 630,000. Songpa is the most populous gu with over 680,000 people in 2016. It was the center of the 1988 Seoul Olympics. Seocho is the largest gu by area and it's a popular middle- and upper-class residential area.