A man on a shark-shaped float enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. A 350 meter-long waterslide has been installed in downtown of Seoul, the longest waterslide to be recorded in Korea, according to local media. (Photo by Kim Hong-Ji/Reuters)

A man holding his daughter enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A 350-meter (1148 feet) long water slide is seen during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A man takes a photographs of his girlfriend on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A man on a dolphin-shaped float enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A girl enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A man enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)

A man wearing a Guy Fawkes mask enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. (Photo by Kim Hong-Ji/Reuters)