Seoul is well connected to the rest of the province and country by rail. There are several kinds of trains in Korea, and each operates to or from Seoul since everything really begins and ends in Seoul! There are four main train stations in Seoul, each in a different district: Yeongdeungpo Station in Yeongdeungpo-gu, Yongsan Station in Yongsan-gu, Seoul Station in Jung-gu and Cheongnyangni Station in Dongdaemun-gu.
The following are the types of trains you can take and from which stations you can take them. Since the port city of Busan is the farthest one can take a train in South Korea, an example price is given for a one way ticket to Busan – this way, you know the maximum price you can expect to pay for any train journey:
Mugungwha: This train operates to all major towns and cities within Korea. It is the cheapest option for rail travel within Korea, but is still considered very comfortable and is a popular option for those with plenty of time but not a lot of money. You can get these trains from any station in Seoul. A ticket to Busan (five hours away) will cost around 25,000 won. This train is also your main option if you’re traveling to a more rural area in Korea.
Saemaul: This class of train operates from each train station in Seoul except Cheongnyangni Station. Unlike Mugungwha trains, you cannot purchase standing room tickets. The seats are more comfortable but they do not run on as many railway lines as Mugungwha trains and are not as fast as KTX trains. You can get to Busan in less than five hours for about 40,000 won.
KTX: As Korea’s newest and fastest train, KTX is by far the most popular among travelers. Although more expensive than the other trains, KTX trains go over 300 km/ph during each trip, and they are widely available on the most popular train routes in Korea (Seoul to Busan or Mokpo in the South). You can hop on the KTX from Seoul Station or Yongsan Station and get to Busan in roughly 2.5 hours for around 50 to 70,000 won one way. The KTX also comes equipped with very hi-speed wifi. You can pay a small fee to receive access to it from one of the many attendants walking around with a snack cart.
For more information on rail travel in Korea you can visit the Korail website in English, where you can also book online: http://info.korail.com/2007/eng/eng_index.jsp.