Festival-goers enjoy the mud during the annual Boryeong Mud Festival at Daecheon Beach on July 18, 2015 in Boryeong, South Korea. The mud, which is believed to have benefical effects on the skin due to its mineral content, is sourced from mud flats near Boryeong and transported to the beach by truck. (Photo by Chung Sung-Jun/Getty Images)

South Korean military soldiers take part in the South Korea and U.S. joint military exercise to commemorate the 63th Korea Armed Forces Day at the Seungjin firing drill ground on September 30, 2011 in Pocheon, South Korea. The exercise is intended to prepare the South Korean defence force for any potential action from North Korea. (Photo by Chung Sung-Jun/Getty Images)

South Korean college students wearing masks hold up candles as they march after a rally calling for South Korean President Park Geun-hye to step down in Seoul, South Korea, Saturday, November 12, 2016. Hundreds of thousands of people flooded Seoul's streets on Saturday demanding the resignation of Park amid an explosive political scandal, in what may be South Korea's largest protest since it shook off dictatorship three decades ago. (Photo by Lee Jin-man/AP Photo)

A man pushes her daughter on a cart as they shop at a market in Seoul, South Korea, July 26, 2016. (Photo by Kim Hong-Ji/Reuters)

A South Korean model poses with Peugeot 5008GT during a press preview of the Seoul Motor Show in Goyang, northwest of Seoul, on March 30, 2017. South Korea's largest international auto show will open on March 31, with a total of 27 brands showing their latest cars and concepts. (Photo by Jung Yeon-Je/AFP Photo)

A woman poses for photographs with traditional side dish Kimchi during the Seoul Kimchi Festival in central Seoul, South Korea, November 4, 2016. Kimchi made with cabbage, other vegetables and chili sauce and kimchi is the most popular traditional food in Korea. (Photo by Kim Hong-Ji/Reuters)

KARA perform on stage during their first solo concert KARASIA at Olympic gymnasium on February 18, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Buddhists carry a dragon-shaped lantern during a lotus lantern parade in celebration of the upcoming birthday of Buddha in Seoul, South Korea, May 7, 2016. (Photo by Kim Hong-Ji/Reuters)