A gathering of regional defense chiefs in the very same city where the two leaders of the United States and North Korea are due to meet in a mere 10 days' time.
While excitement is building, the high stakes nature of the event means secrecy surrounds much of the planning.
Syrian President Bashar al-Assad said he'll meet with North Korean leader Kim Jong Un in North Korea.
U.S. Defense Secretary Jim Mattis said on Sunday North Korea will receive relief only after it takes clear and irreversible steps to end its nuclear program, adding it would be a bumpy road to a summit between U.S. and North Korean leaders.
Seoul reportedly spent somewhere in the range of $5 million to cover the costs of costs of President Moon Jae-in's first summit with Kim in April - a day-long affair that was held in publicly owned buildings on the South Korean side of the Demilitarized Zone.
"This reshuffle has brought to the fore the officers who can do just that".
North Korean delegates led by Kim Chang-son, Kim Jong-un's de facto chief of staff, have also stayed at the Fullerton.
Citing an unnamed intelligence official, Yonhap said No Kwang-chol, first vice minister of the Ministry of People's Armed Forces, had replaced Pak Yong-sik as defence chief, while Ri Myong-su was replaced by his deputy, Ri Yong-gil.
Mr Trump revived the Singapore summit on Friday after cancelling it a week earlier. Sanctions make it very hard for senior North Korean officials to travel overseas, and Madden said Kim will also not wish to impose too much of a burden on the Singapore government, which will have to deal with onerous security arrangements caused by both leaders' presence in the city.
Given the military's secondary role in the North's nuclear and missile programmes, the moves are likely more about installing a younger, even more trusted cohort of officials who Kim Jong Un can rely on as he confronts a variety of domestic and worldwide issues, said Michael Madden, a North Korea expert at Johns Hopkins University´s 38 North website.
Kim and Assad have been accused of co-operating on nuclear weapons by the United Nations, an allegation North Korea denies.
It is unclear whether Kim Jong-un is removing hardliners - who dominated military policy past year, when Pyongyang-Washington tensions were at their apex - from the high command ahead of his upcoming summit with Donald Trump, or is simply replacing old figures. They are loyal to Kim Jong Un and no one else'.
All of the new officials are young than their predecessors, according to Reuters.
"This is where you would send someone you could trust", said Hong Min, head of North Korea research at the state-run Korea Institute for National Unification in Seoul.