ROK JCS Announces That It Will Be Moving to Southern Seoul
|To make way for the Presidential office in Yongsan the ROK military’s Joint Chief’s of Staff office will be moving to Southern Seoul:

The South Korean government plans to relocate the Joint Chiefs of Staff (JCS) headquarters to southern Seoul and seeks to construct its new building there by 2026, the defense ministry said Tuesday.
In a parliamentary policy briefing, the ministry made public the relocation plan, as the ministry’s key offices have occupied parts of the current JCS building since the presidential office’s relocation to what used to be the ministry’s headquarters in Seoul’s central district of Yongsan.
Defense Minister Lee Jong-sup said that the government plans to move the JCS building to the Capital Defense Command in Namtaeryeong, southern Seoul, in the “mid- and long-term.”
Lee estimated that the relocation and the construction of the new JCS building may cost between 200 billion won (US$ 157 million) and 300 billion won, much more than initially expected.
Yonhap
You can read more at the link.