"So many little towns are at risk of disappearing," said demographics researcher Choi One-lack at the Korea Economic Research Institute (KERI). "The pace of ageing and birth declines is the worst here among the OECD."
The population of South Korea, Asia's fourth-largest economy, has become the world's fastest-ageing society with the lowest birth rate anywhere in 2020, according to the World Bank.
The Bank of Korea expects the nation will overtake Japan as the oldest society in the world sooner than 2045 - its earlier projection - as its "fertility rate is declining at a much faster pace than expected"
The nation's fertility rate slid to just 0.84 in 2020 from 4.5 in 1970, Statistics Korea data showed.
Experts predict serious labour shortage problems.
"Losing workforce will be a bigger hit for countries like South Korea, than say Australia or other resource-rich nations, because the very backbone of the growth engine here has been manpower and technologies," said KERI's Choi.
To replenish the workforce, the government plans to encourage more women and senior citizens to work, and create new visas to attract foreign professionals.