The Book of Mormon contains little information about the construction of temples north of the land of Nephi. The only direct reference to the temple in Zarahemla is found in connection with King Benjamin's covenant renewal and coronation speech (see Mosiah 1:18-27). Another reference to a temple in the land of Bountiful is in 3 Nephi 11:1, where the resurrected Lord Jesus Christ appeared to a group of righteous people who had gathered there. Nevertheless, several unnamed temples in the land of Zarahemla are mentioned in Alma 16:13 as places where Alma and Amulek preached repentance. . . .
John Welch postulates that since King Mosiah probably kept control over the temple in the local land of Zarahemla, and since Alma was granted power to organize and administer seven churches independent of royal supervision (Mosiah 25:19,23; 26:8,12), and since others in the church soon became high priests (see Alma 30:20,21), that apparently they officiated at their own local temples. . . .
Lamanite temples in the land southward are referred to in Alma 23:2 and 26:29. The cement construction of temples, synagogues, and sanctuaries in the land northward is briefly noted in Helaman 3:9,14. [John W. Welch, "The Temple in the Book of Mormon," in Temples of the Ancient World, pp. 343,348,362-363]
“Alma and Amulek Went Forth Preaching Repentance to the People in Their Temples”
In Alma 16:13 it states that "Alma and Amulek went forth preaching repentance to the people in their temples, and in their sanctuaries, and also in their synagogues, which were built after the manner of the Jews." According to an article by John Welch, synagogues are mentioned several times in the Book of Mormon. Places of worship were called synagogues during the time of Nephi and Jacob (see 2 Nephi 26:26). Several centuries later, they were still being built by the Nephites "after the manner of the Jews" and were used along with temples and other sanctuaries as places of preaching (Alma 16:13). Later, unusual forms of synagogue worship developed. The Amalekites and Amulonites built synagogues "after the order of the Nehors" in the city of Jerusalem joining the borders of Mormon (Alma 21:4), where Ammon preached. The Zoramites also built synagogues in Antionum (see Alma 31:12), which contained rameumptoms upon which the elect were allowed to pray.
Some points should be noted and explored here. First is the diversity evident in Book of Mormon synagogues. The institution was not rigid. There were synagogues after the manner of the Jews, after the manner of the Nehors, and in Antionum after a manner that amazed Alma and his companions. Similarly, ancient Israelite communal worship appears to have begun as a flexible practice and was known in several developmental stages. It is noteworthy that these very early convocations were for the purposes of prayer and worship, which also seems to be the dominant function of the early synagogues in the Book of Mormon. Nephi expressly calls his synagogues "houses of worship." It is a matter of much scholarly debate when and how the synagogue as known to later Judaism actually developed. The Book of Mormon, of course, lends credence to the idea that synagogues, at least as places of worship, were known to Israel before the departure of Lehi from Jerusalem (although no specific statement makes that claim). [John W. Welch, "Synagogues in the Book of Mormon," in Reexploring the Book of Mormon, p. 193] [See the commentary on 2 Nephi 26:26; Alma 21:4-5, 31:12] [See the commentary on Mosiah 6:3]