In July of 2012 I got to go to Korea to present a paper at ACL 2012 (The 50th Annual Meeting of the Association for Computational Linguistics), and stayed for a few days after the conference to see Seoul. See the full photo set for more pictures.
Flights
The conference was on Jeju island, so that's where I went first via stops in Taipei and Seoul.
Returning, the flight from Incheon to Taipei was (unexpectedly, since I don't think it's known for that route) a Hello Kitty themed A330. This was a bit over the top, but provided free icecream to make up for it.
Jeju
The conference was at the Jeju International Convention Center in Jungmun, Jeju. Jungmun seems to be named for having a lot of Chinese speakers (it's Korean for 中文). It has many hotels and resorts.
Next to Jungmun is Seogwipo, which is more of a city. The area has several waterfalls which are supposed are mostly supposed to have dragons or faeries. One was also supposed to have giant eels which I thought might be more plausible, but unfortunately I didn't see any dragons, faeries, or eels. There are also some hexagonal rocks by the ocean.
Jeju has statues called Dol hareubang, now mostly mass produced tourist ones but with some old carved ones too. Although there is potential phallic symbolism that fits with modern associations of Jeju, Wikipedia notes that they are more likely related to a past magic mushroom cult.
Seoul
City
I was staying most of the time at Bong House hostel near Hyehwa subway station.
Insadong is maybe the main tourist area, I believe for both Koreans and foreigners of various types.
Myeongdong is a trendy shopping area, and also popular with tourists of the buying-things type, I think especially Japanese tourists.
Between Insadong and Myeongdong is Cheonggyecheon, a stream that was previously covered over but was recently restored. There is a also a more business-type area.
South(ish) of Myeongdong is a hill park with N-Seoul Tower at the top.
North of all of that is Samcheongdong, which is smaller and with more traditional buildings. It has a lot of restaurants and galleries like Insadong, but more spread out.
The Hongdae area near Hongik University is a bit west of the main tourist areas. It's largely a nightlife area, for locals and some tourists.
I also went to Yongsan electronics market to look for a mechanical keyboard.
Apgujeong is a trendy shopping area in Gangnam, south of the river.
Other parts of the city I usually don't know names for.
Palaces, temples, and burial mounds
Seoul has five palaces which are at the north edge of what I guess is the city centre. I think I went to all of them, although I seem to only have pictures from four.
Samneung tombs is more or less a city park in Gangnam, but contains burial mounds from the 15th and 18th centuries (I think).
I also visited Jogyesa temple (in Insadong) and Bongeunsa temple (in Gangnam, nearish to Samneung tombs).
DMZ
I didn't do the full DMZ tour, but the half-day tour where we were taken to the edge of the DMZ but not into the Joint Security Area. This included a stop at a rest stop at the edge of the military area featuring food shops and a small amusement park, a visit to the Third Tunnel of Aggression, a stop at a viewpoint at the edge of the DMZ, and a visit to the last train station on South Korea's line going north, which is currently not in service.
Miscellaneous notes
Korea often seems to have two-lane crosswalks, presumably one for each direction. Sometimes people actually follow these, but not too often.
There are frequent tall churches in the cities.
Raw food markets and underground malls are similar to Taiwan. I never got to see a night market in operation in Korea. They don't seem to be too common but there are a couple of big ones in Seoul.
The subway system in Seoul is extremely extensive, with hundreds of stations. It's a bit hard to navigate, but convenient. However, some of the stations are small and cramped.
Both Jeju city and especially Seoul have many large apartment blocks consisting of rows of duplicated large buildings. There are a few styles, and some of them seem fairly nice, with little attached parks.
Korea is quite expensive and vegetarian food is hard to find.