The Arch of Kings was the original name for Kerath's Arch. The name was changed after King Kerath voluntarily abdicated the throne in 6977 DE. According to DRC research, it was constructed as a copy of the Arch of Kings on Garternay, the original D'ni homeworld. The prophecies of Oorpah which dealt with the coming of the Great King revolved around the Arch of Kings, and as such, it was a project of considerable priority once the D'ni were settled in the cavern.
DRC Research. King Ja'kreen Notebook