With one of the lowest birth rates in the world, South Korea is in danger of disappearing by the end of the millennium. If the situation stays as it is, South Koreans are predicted to become extinct by 2750.Because of the rapidly ageing population, elderly prostitutes known as "Bacchus ladies" have cornered a number of public parks as their working areas. Meanwhile, as the marriage rate falls and the country's younger generation continues to live at home well into their twenties, young people have been forced to book themselves into purpose-built sex motels to avoid the prying eyes of parents.We sent Matt Shea to investigate this generational crisis, which led him to Seoul's Red Light District, a pre-wedding photo-shoot on the set of a Korean soap opera, and an erotic sculpture park on South Korea's "honeymoon island".@RDRhysJames / @avantgrant / @Matt_A_Shea