Nephihah was the place that the Nephites fled to later when the city of Moroni was attacked by Amalickiah, (see Alma 51:22-27 for more details). Nephihah was a place of gathering from the conquered cities of Moroni, Lehi, Morianton, (see Alma 59:4-8 for more details). The Lamanites fled to the land of Moroni when the city of Nephihah was reconquered by Pahoran and Moroni coming from the (local) land of Zarahemla, (see Alma 62:14-26 for more details) Thus, Nephihah's location would perhaps be not only near, but somewhat equally convenient to each of these areas, otherwise why would they gather to Nephihah and not to another city?
The city of Nephihah might have been located somewhat inland. In Alma 51:26 after listing the cities of Nephihah, Lehi, Morianton, Omner, Gid and Mulek; Mormon says that they all "were on the east borders by the seashore. The city of Aaron is conspicuously absent from this list of cities. However, in Alma 50:14, Nephihah is said to be "between the city of Moroni and the city of Aaron, joining the borders of Aaron and Moroni." For this reason we can possibly assume that the city of Aaron was somewhat near to the city of Nephihah. The only other place in the Book of Mormon where we read about a city called Aaron is in relation to Alma's missionary journey in the Land of Zarahemla. Alma left the city of Ammonihah and was going toward the city of Aaron. (Alma 8:13-14) The city of Ammonihah was three days travel on the north from the land of Melek, and the land of Melek was on the west of the local land of Zarahemla. Therefore, the city of Aaron may have been west of Nephihah, and Nephihah, being the first contact traveling eastward from the city of Aaron, might have been more inland than the other cities mentioned. [See Geographical Theory Maps]