You are thinking of the Gaza Strip down by Egypt. That area has always been predominantly Palestinian - about 2 million people or so. There were some small settltements that had to be abandoned. I remember the "settlers" being dragged from their homes on the news when this happened. Israel allows Gaza to self govern but all its electricity comes from Israel. There has been an air and sea blockade of Gaza since day one and there is no freedom of movement into or out of Gaza for obvious reasons. This occurred in 2004 or 2005 - I can't remember.
However, this was proposed by Israeli PM Sharon, a known dove, and approved by the Knesset. Bush supported it.
I think it is fair to say this was a mistake for all kinds of reasons.
The Golan Heights is completely different. It borders Syria and is a very strategic area for Israel because it overlooks Syria. Israel won it back for the first time in the 6 Day War in 1967 and would never give it up for any reason.