Slang for Dong Ap Bia Mountain. Bloody battle durring the Vietnam War fought in May of 1969 between America's 101st Army Airborne, with help from the Army of the Republic of Vietnam (ARVN, South Vietnam) against the North Vietnamese Army (NVA). After some 10 days of fighting, the US eventually took over the hill, NVA finally realizing they weren't going to successfully defend the hill and staying to fight would be foolish, so they retreated.
The hill itself however turned out to have no tactical advantage in the war and was criticized by many in the states to have been a useless battle where many were lost. 56 Americans were killed, 420 wounded. Some 597 Vietnamese were killed.
"No matter how tough the job is, the American soldier gets the job done. He might hate the hell out of it, but he never quits. In Hamburger Hill, they might have grumbled, but my God they were there when the chips were down. They eventually went up that hill and took it!"
-Colonel Joseph B. Conmy, Jr., Commander of 3rd Brigade, 101st Airborne Division
My vibrance will span to Negril
With the violence of Hamburger Hill
-Vinnie Paz of Jedi Mind Tricks