The Seoul City Wall

Eighteen and a half kilometres of wall built in 1396 around the new capital, running over four mountains and linking eight gates. Something like twelve kilometres of it survives or has been rebuilt, and you can walk almost all of it.

It is the single best thing to do in Seoul and it costs nothing. The wall goes up and over the ridges rather than round them, so you spend an afternoon climbing through pine woods with a ten-million-person city on both sides of you, and then come down a staircase into a neighbourhood.

What it costs

⭐ Free, and there is no gate to be closed. This is the one major sight in the city with no opening hours at all.

⚠️ The exception is the Bugaksan section behind the palace, which runs past the presidential compound; it has been progressively opened but sections can still carry restrictions and photography rules. Check that stretch specifically before setting out.

When to go

Any daylight. Autumn is the obvious answer — clear air, and the whole ridge turns.

⚠️ It is a hill walk, not a stroll: proper shoes, water, and more time than the distance suggests.

Getting there

The six official sections each have their own start. The easiest is Naksan: Hyehwa station, line 4, exit 2, up through the park, and down to Heunginjimun. It is about two hours, it is the gentlest gradient, and the view back over the old city is the classic one.

For the hardest and best, start at Changuimun and cross Inwangsan.

If you only have an hour

Naksan is the right first section. Up from Hyehwa, along the top with the wall on your left and the rooftops falling away on your right, past the Ihwa mural village, and down to Heunginjimun — Dongdaemun, the east gate, marooned on a traffic island with its distinctive extra half-moon wall built round it, because the ground here was soft and needed the reinforcement.

Then the DDP is five minutes south and Gwangjang Market is fifteen west.

What people get wrong

Trying to do all eighteen kilometres in a day. Six sections exist for a reason; do one properly.