Since the detachment's mission was the security of the 5th Special Forces Group Headquarters and the Nha Trang air base, it was located with a South Vietnamese LLDB unit that was strategically located within A-502's TAOR (Team Area Of Responsibility).

     In 1965, 5th Group Headquarters determined the need for two A-Teams in the Nha Trang area, but with each having different responsibilities.  This determination resulted in the authorization and establishment of Detachment A-503, which would assume the responsibilities of A-502.  Because of their familiarity with the mission, key members of A-502 were assigned to the new team.  The XO (Executive Officer) of A-502 became the CO (Commanding Officer) and Team Leader of the new A-503 team.

     Released from its original assignment, A-502 was given an even greater mission.  It would become responsible for the security of the entire Nha Trang area.  Overnight, the team's AO (Area of Operation) and responsibilities became significantly larger.   With the acceptance of its new mission, A-502 would also begin to create its history as the largest Special Forces A-Team ever to exist.

     French forces occupied South Vietnam prior to the involvement of the United States.  The fort was originally constructed by the Vietnamese under the Nguyen Ahn dynesty in 1793.  It was home to units of the French foreign legion's 2nd Colonial Infantry beginning in the early 1940's and could have easily served as a set for an old Humphrey Bogart movie.  However, in 1945, the Viet Minh attacked and overran the fort, claiming the strategic location for themselves.  After being held by these enemy forces for several months, it was retaken by the French in a coordinated counter-attack.  Reinforcing units of the 6th Colonial Infantry were landed in Nha Trang.  Linking up with General Leclerc's 2nd Armored Division Task Force, the two units mounted their counter-attack and reclaimed the fort they had dubbed the "Dien Khanh Citadel."

     The picture above was taken in 1968 and shows the fort's eastern entrance.  While the picture was taken in the late 60's, aside from the telephone pole, the entrance appears much as it did when occupied by the French Colonial Infantry.  The picture below was taken in early 2000 and shows the fort's eastern enterance as it appears today.  Amusing to someone who was there fighting a war, but passage through the entrance is now controlled by traffic lights.

     After occupying the fort, the team that had started as a 12 man unit began to grow and add outposts.  A-502 reached its maximum unit size in 1968 when it had approximately 56 team members. Vietnamization, the act of turning complete responsibility for the Vietnam War over to the Vietnamese, began to impact the team in mid to late 1968.  When vacated positions were not replaced, team members began taking patrols and night ambushes to the field alone.  Previously, at least two team advisors went out with every unit. During the balance of 1968 and throughout 1969, A-502 team numbers continued to shrink.  Then, in January of 1970, A-502 was officially closed.