Seoul is a very compact city with lots of interesting stuff to see. There are still pockets of small wooden houses (Hanok) that used to cover Korea before modernisation got rid of them, old royal palaces and the general madness of modern Korea. Food is excellent, if you like it spicy and it pays to be adventurous! English is widely spoken and itis possibly the most concious place on the planet.
When I am old I shall wear purple with a red hat, which does not go.