Here are a few other places we've been to in Seoul that might be of interest:
Presseum. Newspaper History Museum. The best part of this little museum in the Dong-A building (it's beside the new sculpture at the start of the Cheonggyecheon), is the exhibition of over 100 front pages of newspapers from around the world from their Jan 1st 2000 edition. Trying to guess the country of the less obvious ones was a good game.
They have a nice shiny brochure in English which makes it sound interesting and informative, but all the exhibits are in Korean (as you'd expect) unfortunately there is no English explaining any of them. On the top floor you can have your photo taken, enter some text and they print the front page of that day's paper with your photo replacing the main picture for you to take away! Not great value at 3,000 Won each. ( They had a website www.presseum.org, but they seem to have let the registration expire!)
The Agriculture Museum, Not an inspiring name, but actually turned out to be very interesting. Lots of large dioramas over three floors telling the story of food production in Korea through history. They also have very realistic reconstructions of a village and shops and houses in old Korea. The handset in English was a waste of time and did not add anything to the English exhibit descriptions. Free admission.
Contemporary Art museum. This is out at the Seoul Grand Park, so a bit of a trek out on metro line 4 to get to. Skip the "elephant ride" road train. It's 800 won for a 2 minute ride that is almost quicker to walk. Also out there is the Zoo, Seoul Land amusement park and a Botanical garden. In the museum the huge installation in the foyer with hundreds of TV screens showing bright, fast cutting images is very eighties. There are plenty of lines, swirls, blotches, plain colours and stockings in the artwork to enjoy.
Bukhansan. (again) I tried another route into the park recently. About 10 or 15 mins walk from Soyu station on Line 4 is the Hwagyesa entrance, which, when I went, was deserted. From there I climbed to Daedongmun which is a gate in one of the fortress walls. It was quite a difficult path from that side, but going back I arrived at Jeongneung ticket booth along a very easy path. My good friend Erkin took some photos when he was there.