This is where the final battle will be fought.
And he gathered them together into a place called in the Hebrew tongue Armageddon [Rev. 16:16].
"This is the only occurrence of the word Armageddon in Scripture, although there are many references to it. It means “Mount of Megiddo.” It is a compound word made up of the Hebrew words Har, meaning “mountain,” and Megiddo, which is a mount in the plain of Esdraelon. I have been there several times. It is one of the most fertile valleys I have ever seen. I guess it is the most fertile valley in the world today. It is a place where many battles have been fought in the past. Vincent cites Clarke’s Travels regarding Megiddo in the plain of Esdraelon:
… Which has been a chosen place for encampment in every contest carried on in Palestine from the days of Nabuchodonozor king of Assyria, unto the disastrous march of Napolean Bonaparte from Egypt into Syria. Jews, Gentiles, Saracens, Christian crusaders, and anti–Christian Frenchmen; Egyptians, Persians, Druses, Turks, and Arabs, warriors of every nation that is under heaven, have pitched their tents on the plain of Esdraelon, and have beheld the banners of their nation wet with the dews of Tabor and Hermon.
“He gathered them together.” The “he” is possibly God Himself. Although Satan, Antichrist, and the False Prophet act in unison to force the nations of the world to march against Israel, they nevertheless fulfill the Word of God." McGee, J. V. (1991). Thru the Bible commentary: The Prophecy (Revelation 14-22) (electronic ed., Vol. 60, pp. 82–83). Nashville: Thomas Nelson.