What army post is at the dmz?

Answer 1

It's a United Nations installation, which was staffed by personnel from both the US and ROK Armies, although I believe US troops are being removed from there. The combined unit is known as the United Nations Council Service Battalion, and the name of the camp(s) where they're stationed (it's essentially two camps which are joined together) are Camp Bonifas (named after the US Army officer murdered in the 1974 Panmunjom axe murders) and Liberty Bell.

The northernmost US installation which was not subordinate to the UN was Camp Greaves, which, during my time there, housed the whole of the 1st Battalion/506th Parachute Infantry Regiment (though they're not actually a parachute unit anymore), minus A Company, who were south of the Imjin River at camp... I can't think of the name offhand. It was often referred to as Camp Gator.

The colours of the 506th PIR were returned to the 101st Airborne (they're not a jump unit anymore, either), which was their historical home. Camp Greaves was shut down circa 2004 or 2005, and handed over to the ROK armed forces. Last I heard, it remains unused.