Up until Friday, the government has denied their requests to travel to the complex, apparently worrying that it could signal that the two Koreas are preparing to reopen the industrial park despite Washington's push to keep crushing sanctions in place against North Korea amid little progress in denuclearization talks.

The decision to allow their trip came as Seoul has been trying to keep the peace process with the North alive despite the North's firing of missiles and projectiles earlier this month. Seoul is also formulating plans to send food aid to the impoverished North.

Launched in 2004, the industrial park in Kaesong was born on the back of a peace mood created after the first-ever inter-Korean summit between South Korean President Kim Dae-jung and North Korean leader Kim Jong-il in 2000.

It was hailed as a symbol of inter-Korean economic cooperation and a successful cross-border project that combined South Korean capital and technology with cheap labor from North Korea.

Its operation, however, came to an abrupt halt when the Seoul government announced in February 2016 that it would shut it down to punish the North for its nuclear and missile provocations. About 120 companies were operating there when the closure was announced. (Yonhap)