Iraq's Fao Peninsula (sometimes transliterated Faw Peninsula) is the southernmost part of the country, extending into Shatt al-Arab waterway between Iran, Iraq and Bubiyan Island.
It has been important in multiple wars. With modern weapons, is sufficiently close to the Iranian landmass that it can be put under artillery and missile fire even without invasion. Even more important, however, is dominating the Shatt al-Arab. 
First World War
During the Iran-Iraq War, it was the site of especially heavy fighting between February 1986 to April 1987.
In the Iraq War, it was taken by Royal Marines, again using it to attack Basra. As U.S. Marines moved into the Rumaylah oil field, British forces took control of the Fao Peninsula oil facilities, as well as the port of Umm Qasr. U.S. Navy SEALs captured some of the offshore facilities. A U.S. Marine helicopter crashed, killing Marines from both countries. 
It became an oil port in 1951, and supported offshore plaftorms. The submarine cable to India land there in 1954.
- Youssef Aboul-Enein (June 2005), "The First World War Mesopotamian Campaigns: Military Lessons on Iraqi Ground Warfare", Strategic Insights
- Andrew Buncombe in Kuwait City (March 22, 2003), "Burning oil wells may have caused death of marines", Independent (U.K.)