Forward Operating Base 4

Forward Operating Base 4 (also known as FOB 4) is a former Military Assistance Command, Vietnam – Studies and Observations Group Command and Control North base near the Marble Mountains, Vietnam.

History
The base was located immediately north of the Marble Mountains and south of Marble Mountain Air Facility.

On the night of 22–23 August 1968, as part of their Phase III Offensive, a company from the Viet Cong (VC) R20 Battalion and a sapper platoon infiltrated the base, killing 17 Special Forces soldiers (their largest one-day loss of the war) and wounding another 125 allied soldiers, 32 VC were killed.

Current use
The base is abandoned and the area now consists of sand dunes with some commercial/residential development.