a place full of cliffs, canyons (see Molina); water could be involved, given the meaning of atlauhtontli
Alonso de Molina:
atlauhyo. lugar barrancoso. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 8v. col. 1. Thanks to Joe Campbell for providing the transcription.