N Seoul Tower (Namsan)

N Seoul Tower sits on top of Namsan Mountain in the centre of Seoul — a 236-metre communications and observation tower that has been the city's most recognisable landmark since 1975. The tower is visible from virtually every neighbourhood in central Seoul, and the view from the observation deck — a 360-degree panorama that takes in the Han River, the palace district, the Gangnam skyline, and on clear days the mountains of North Korea 50 kilometres away — is the one view that makes Seoul's geography comprehensible.

Getting to the tower is part of the experience. The Namsan Cable Car, running since 1962, carries you from the base of the mountain to a plaza near the summit in a few minutes. The alternative — walking up through Namsan Park, a forested hillside threaded with paths and stairs — takes about 30 minutes and passes through one of the few patches of mature forest in central Seoul. The park is popular with walkers and joggers, and the combination of mountain air and city views makes the climb feel more like a countryside hike than an urban walk.

The tower base has become famous for the 'love locks' — thousands of padlocks attached to fences and railings by couples who write their names on the locks and throw away the key. The tradition, popularised by Korean dramas, has made the tower one of the most popular date spots in Seoul. At night, the tower is lit with LED lights that change colour based on the day's air quality — blue for good, green for moderate, yellow for unhealthy — turning the city's most visible structure into an environmental indicator that 10 million people can read at a glance.