Monkey Mountain Facility

Monkey Mountain Facility (also known as Monkey Mountain SIGINT, Hill 621 or Panama) was a U.S. Air Force (USAF) and Marine base located on Sơn Trà Mountain east of Da Nang.

History
The base was located south of the peak of Sơn Trà Mountain, overlooking Danang Harbour and China Beach

The USAF Detachment 2, 6925th Security Group established a signals intelligence (SIGINT) base on the mountain in 1962 to intercept North Vietnamese HF and VHF communications.

The USAF 620th Tactical Control Squadron established a control and reporting post (CRP) code-named Panama on the mountain in 1964 to support operations from Danang Air Base. On 14 February 1965 the Marine 1st LAAM Battalion established its anti-aircraft operations center colocated with the USAF CRP. The MIM-23 Hawk missiles of A Battery, 1st LAAM Battalion were also deployed on the mountain approximately 5 km south of the CRP. The USAF retained overall control of air defense around Danang and the CRP controlled when and if the Marine Hawk missiles could be fired.

In August 1965 the 9th Marines assumed responsibility for the defense of the Monkey Mountain area.

On 26 October 1965 two F-4B Phantoms of VMFA-115 returning to Danang Air Base from a mission crashed into the side of Monkey Mountain killing all four crewmembers.

In late 1966 the USAF established a new tactical air control - north center (TACC-NS) at the base which controlled all air operations over North Vietnam.

In July 1967 Marine Air Control Squadron 4 (MACS-4) established a new Marine Tactical Data System (MTDS) and Tactical Air Operations Center (TAOC) allowing for the control of up to 200 aircraft at once and a direct link to the Seventh Fleet's Naval Tactical Data System.

On 24 March 1968 an F-8 Crusader Bu 150306 from VF-53 crashed into the side of Monkey Mountain, the pilot ejected successfully and the rear fuselage of the jet which embedded in the mountain became a popular photo opportunity for military personnel.

In July 1969 the 1st LAAM Battalion was withdrawn from Vietnam.

In February 1971 MACS-4 was withdrawn from Vietnam, however 20 Marines from the Squadron remained at Monkey Mountain to man the TAOC.

In March 1971 the USAF SIGINT facility was closed and its operations were moved to Thailand.

Current use
The base has laregly reverted to jungle although a modern radio tower has been built at the site.