To travel from city to city in Korea, taking a train is probably the most safest and the best way as a foreigner.
There are several types of trains in Korea.
1. Regular Trains
a) KTX : It’s the fastest train in Korea. By taking this train, it takes less than 3 hours from Seoul to Busan. Although the train fee is expensive, you can save time with high quality seats. If you go to Busan from Seoul by Mugunghwa train or a car, it takes more than 5 hours.