Moronihah Mountain is a mountain formed where the city of Moronihah stood. “And the earth was carried up upon the city of Moronihah, that in the place of the city there became a great mountain” (3 Nephi 8:10).
Moronihah was “that great city Moronihah” covered with earth along with its inhabitants. It was covered “to hide their iniquities and their abominations from before my face” (3 Nephi 9:5).