Namsan Park had a strategic military purpose during the Joseon Dynasty when the capital moved to Seoul. Today, is a park with lovely views of the city. The 236m N Seoul Tower sits o top of the hill and opened to the public in 1980. While there is a cable car from Myeongdong to the tower, it is also possible to walk a sloping incline that is well-paved and relatively easy.
Even before reaching the top, views of the city were already quite nice.
Even if you won't pay the admission fee to go up the tower, the open spaces at the base already are very scenic.
Head across to the other side where there is another observation area facing the historic centre of the city.
N Seoul Tower has been renovated and rebranded. Nevertheless, the views are still the same - definitely worth a visit.
There is also a staircase leading back down to near Myeongdong, which is more strenuous if going the other way than the sloping street on the other side.