The Great Church of Gaci was an enormous place of worship in Gaci, capital of the Holy Moti Empire. Constructed from 562 SR onward, it was intended to be one of the centerpieces of Motian Iralliam, a symbol of the patronage of the Ayasi, and possibly as a subtle jab at the Ayasi's rival, the Grandpatriarch of Opios. By the first decade of the project, it was already the largest temple in the world, and one of the great marvels of classical engineering.
The vaulted ceiling of the central worship hall rose more than a hundred and fifty feet in height, and the hall itself extended over five hundred feet in length. Either side was lined with stained glass windows, bearing numerous geometric designs that allowed a multitude of lights to pour over the sculptures and reliefs of the walls and edifices within -- each of them telling stories of the life of the Prophet Kleos. It was intended that a casual observer, walking from the south entrance counterclockwise, could essentially learn the full story of the Prophet's deeds, and much of his teachings, simply from the sculptures he passed -- and from the occasional inscription.
Despite its size and splendor, ecclesiastically, the Church was "merely" the seat of the Patriarch of Gaci, one of the many subordinates of the Grandpatriarch.