Jirisan

Set against the backdrop of towering views of Mount Jiri, it depicts the story of rangers and other employees of the Jirisan National Park who climb through the mysterious and unexplored regions of the mountain, trying to rescue the survivors and lost trekkers. The drama is centered around a mystery surrounding the mountain's many visitors; those who come to kill, and those who come to end their lives.  [About] Jirisan (Cliffhanger) is an upcoming South Korean television series starring Jun Ji-hyun, Ju Ji-hoon, Sung Dong-il and Oh Jung-se. It is scheduled to premiere on tvN in 2021 and will be available for worldwide streaming through iQIYI. [Source: Wikipedia]