Terrah is the home of the Earth Ashari, located in a bowl-like valley in the center of the Cliffkeep Mountains north of Kraghammer. The area experiences constant seismic activity, causing the ground to shake and shudder frequently, and sometimes causing the earth to spike upwards where two plates collide.
The Earth Ashari are very secretive about the location of Terrah and warned Vox Machina not to tell anyone where they were.
Terrah is a village of 673 people, made up of humans (64%), dwarves (21%), and other races (15%). Considering that genasi on Tal'Dorei are most common among the Ashari, this presumably includes earth genasi.