St. Astvatsatsin Church in Haghartsin (1281) is the largest building and the dominant artistic feature. The sixteen-faced dome is decorated with arches, the bases of whose columns are connected by triangular ledges and spheres, with a band around the drum’s bottom. This adds to the optical height of the dome and creates the impression that its drum is weightless. The platband of the southern portal's architrave is framed with rows of trefoils.
The sculptural group of the church’s eastern facade differs in composition from the similar bas-reliefs of Sanahin, Haghpat, and Harich. It shows two men in monks’ attire who point with their hands at a church model and a picture of a dove with half-spread wings placed between them. The umbrella roofing of the model’s dome shows the original look of the dome of Astvatsatsin church. The figures are shown wearing different dresses — the one standing right is dressed more richly than the one standing left. The faces, with their long whiskers, luxuriant combed beards and large almond shaped eyes, are also executed in different manners. These are probably the founders of the church, the Father Superior and his assistant.