Shemlon was a Lamanite-held land bordering the cities Lehi-Nephi and Shilom, in the land of Nephi. Around 200 B.C., King Zeniff sent spies into Shemlon to discover the Lamanites’ preparations and guard his people against attack (Mosiah 10:7). King Noah3 later built a high tower near the temple, from which he could overlook both Shilom and Shemlon (Mosiah 11:12).
Around 145 B.C., when Gideon had pursued Noah3 to that tower, the king looked toward Shemlon and saw a Lamanite army already within the borders of the land (Mosiah 19:6). The priests of Noah3, who had fled their court and remained in the wilderness, found a place in Shemlon where the daughters of the Lamanites gathered to sing and dance; they seized twenty-four of the women and carried them into the wilderness (Mosiah 20:1-5). Afterward Amulon, one of these priests, gained favor with the Lamanite king and was appointed, with his brethren, as a teacher over the people of Shemlon, Shilom, and Amulon (Mosiah 24:1). The inhabitants of Shemlon were later among the Lamanites converted to the Lord through the ministry of Ammon and his brothers (Alma 23:8, 12).
Shemlon lay within the wilderness surrounding the land of Nephi, the same expanse in which the Lamanite army that pursued Limhi’s people became lost for many days and came upon Noah3‘s priests, while Alma1‘s people fled eight days’ journey to settle the land of Helam (Mosiah 23:3-4, 23:30-31).