Mudfest, one of the most famous summer events in Korea, is an attraction to both Koreans and foreigners. Held annually over the span of two weekends, this festival of mud is a must-see if you're teaching English in Korea in the summer. It is held in the city of Boryeong (or Daechon), and it is about two and half hours by train south of Seoul. The city is known for the natural mud flats. According to my friend Wikipedia, this festival was founded to promote cosmetic products made with the mud, since it's said to be full of minerals. I haven't seen much of a change in my skin after playing in the mud, but it was another excuse to play around in it.