Seoul Subway is composed of 16 lines and 546 stations. Although it seems really big, Seoul Subway is quite easy to use. The travel fare is 1,250 KRW if you have a transportation card (T-money more information on the card here) and 1,350 KRW if you don’t have a card.
Seoul has a large bus system. When you will arrive at Seoul, you will notice four different buses.
The blue colored buses run on long distance routes and usually operate at higher speeds than the other colored buses. Blue bus routes connect areas outside central Seoul to downtown Seoul. The Green ones operate on short distance routes and run at slower speeds as they stop at most major subway stations and bus stations outside the center of Seoul. Red colored buses operate on express routes. Like the blue bus route, red buses connect areas outside downtown Seoul. And finally, the yellow colored buses operate on routes that circle areas within downtown Seoul. Yellow bus routes stop at railway stations, tourists sights, shopping and business areas, and blue bus stops which allow connections to areas outside downtown Seoul.
The fares vary depending on the color of the bus. The fare for green and blue buses is 1,200 KRW. For the red buses it is 2,300 KRW while the yellow buses’ fare is 1,100 KRW. Those fares are only for those who possess a T-Money card.