Currency and Exchange
Korean won (KRW) consists of four kinds of notes: 1,000 - 5,000 - 10,000 and 50,000 won and 4 different coins: 10, 50, 100 and 500 won. Buses usually only take 1,000 notes and coins and you may experience that when riding the bus, the bus driver will refuse to let you on board if you try to give him a 10,000 note and don't have change on you. Coins are usually not in use these days, due to inflation. Having such small denominations in the Korean currency, means that you might feel like you're carrying around a very large amount of cash, which you are, but adding up, it might not actually be a lot of money.
The best way to bring money into Korea is exchanging your local currency into US Dollars or Euro. You can exchange most currencies into Korean won via any major banks or money exchangers in Korea. However, you may have trouble exchanging some particular currencies (e.g. Chile, Cuba, Iraq, Libya, etc.) as local banks in Korea do not provide exchange service for those particular currencies. This is why we recommend exchanging them into US Dollars or Euro before you go. Apart from that, withdrawing money at an ATM or paying with credit card will always work in Korea. Some ATM's do not take foreign cards. But most ATM's in subway stations, convenience stores and major hotels always accept foreign credit cards and also foreign language options. Korea Exchange Bank (KEB) always have ATM's that accept foreign cards and menu in English.
No matter which airport you fly into, Incheon International Airport or Gimpo Airport, you will have plenty of opportunities of exchanging your money into Korean won. The best and safest place is any major bank branch or money exchange and yeah...you can exchange your money in Myeongdong or in any major tourist spot in Seoul, like Dongdaemun (another great shopping area in Seoul btw). Keep in mind though, that you should be extra careful to confirm that any money exchanger you are using is legitimate. Hope you'll have a great time and...shop till you drop.