Cities Of The Plain
Holman Bible Dictionary 
Genesis 14:1 Genesis 19:24-29
Most recent scholarship has located the five cities in the shallow water of the southern end of the Dead Sea, south of the Lisan, the tongue of land along the southeastern shore that protrudes into the sea. However, no conclusive evidence has been found to support this proposal. Excavations along the eastern shore of the Dead Sea in recent years have convinced some scholars that the cities of the plain might be located in that region, especially at Bab-ed-Dhra and Numeira near the Lisan.
The particular phrase, “cities of the plain,” occurs only in Genesis 13:12 as the place Lot chose to dwell, and in Genesis 19:29 concerning the destruction. The Hebrew word translated “plain” more nearly means “round.” Thus it seems better to think of these cities as being ones “around” the Dead Sea or “around” the Jordan Valley. This interpretation may indicate simply that these cities were allies that lay in the Jordan Valley near the Dead Sea. As such, these cities may have been on a trade route and themselves involved in the trade of bitumin, salt, and sulphur.
Joel F. Drinkard, Jr.
Hastings' Dictionary of the Bible 
Cities Of The Plain . See Plain [Cities of the].
The Nuttall Encyclopedia 
Sodom and Gomorrah, with adjoining cities under the like doom.