Korea as a whole gained its independence from Japan in 1945, and South Korea's capital city was renamed Seoul. In 1950 the Korean War started, killing around 5 million people in 3 years and destroying a large amount of Seoul. Now the city has been rethought and rebuilt, but it's known for it's population density, Seoul has a population of over 20 million, making it the world’s second largest city behind Tokyo.The people work particularly lengthy hours, and even the students study long and hard, but Seoul has the highest estimated national IQ in the world. With high tech being such a huge industry in Seoul (Samsung and LG are based there) a staggering 95 percent of Korean households have broadband connection, and it has one of the fastest speeds in the world.