N Seoul Tower (known as Namsan Tower before its renovation a few years ago) is probably the most well-known landmark in Seoul. How could it not be when it's seen from just about anywhere in the city? It sits on top of Namsan, a small mountain in the middle of the city, just north of the Han River. I visited the tower once, for my 100th day in Korea celebration. The observatory has a view of the whole city. It's an amazing sight, especially at night.