=Situation of Rabbath-Ammon.= The decisive battles of this campaign were fought near or in Rabbath-Ammon. The city was surrounded by rolling plains, especially on the west, which offered ample opportunity for the manœuvring of armies. The strength of the city itself consisted in its huge acropolis, surrounded, like Jerusalem, by deep valleys. On the north it was connected with the surrounding hills by a low, narrow neck of rock. At this point were built great protecting walls and towers. The hill itself consisted of three terraces rising from east to west, with a main gateway on the south side. Each of the succeeding terraces was defended by a wall. The highest area, which included several acres, rose nearly three hundred feet above the surrounding valleys, and it was, therefore, the largest and in many ways the strongest natural fortress in all Palestine.
=The Water City.= The Water City,^{ (96)} which was first captured by Joab, was probably in the valley of the Jabbok, which runs along the southern side of the acropolis. This valley, and that which comes in from the north along the western side of the acropolis, is the site of the modern city of Amman. The great Roman city was also built for the most part in the Valley of the Jabbok, or, as it is now called, the Wady Amman. Here the waters of the brook, which were carried by aqueducts along different levels and which were supplemented by gushing springs, fully justify the name of Water City. Situated in the valley, it was most exposed to the attack of the Hebrews. When it was captured, the supply of water and food would be cut off from the citadel above, so that, as indicated by the biblical narrative, the fall of the entire city would be the inevitable result of a long siege.
=Extent of David's Empire.= The conquest of the Ammonites and the Moabites and the defeat of the Arameans enabled David to extend the bounds of his empire to the desert. In the northeast it probably never extended beyond Mount Hermon, which was its natural boundary in that direction. In the south he fought a decisive battle with the Edomites in the Valley of Salt, which was probably at the southwestern end of the Dead Sea near the border line between southern Judah and Edom. This Arab race, in its difficult mountain fastnesses, was held in control by means of Hebrew garrisons established throughout the land. By this means David's southern boundary was extended to the eastern arm of the Red Sea and the Sinaitic Peninsula, thus attaining in every direction its natural barriers. In less than one generation, as a result of the energy, tact, and broad statesmanship of David, the physical limitations of Palestine were overcome and a strong empire was established along the southeastern Mediterranean.