Ammonihah is a city in western Zarahemla where Alma goes to preach after preaching in Melek. The citizens of Ammonihah had drifted from the truth, and do not receive Alma. Alma then meets Amulek near Ammonihah, and the duo then confront Zeezrom. Despite their successes in preaching, Alma and Amulek are forced to witness the mass execution of the believers, then are cast into prison. After a miraculous escape, they flee to Sidom. Ammonihah is later completely destroyed by Lamanites who are angry after slaughtering numerous Anti-Nephi-Lehites. The city is then referred to as the ‘Desolation of Nehors’.
It seems odd that the Lamanites would be able to travel to Ammonihah undetected so quickly, suggesting that that there is an alternate route to Ammonihah following the coast, and the city is accessible via a mountain pass. After its destruction, Moroni rebuilds and fortifies the city to the point that the Lamanites do not dare attack it.