The cathedral is a domed, centrally-planned basilica. According to Richard Krautheimer it derives its plan from that of the 7th century cathedral of Talin, with only minor differences. The dome was supported on pendentives and stood atop the "intersection of four barrel vaults elevated to a cruciform design and topped with gabled roofs." In the interior, "freestanding piers divide the space into three aisles, the nave of which terminates in an eastern apse flanked by two story side chapels." Sirarpie Der Nersessian noted that its interior is imposing "through the harmony of the proportions." She added, "The blind arcade with slender columns and ornate arches, the delicate interlaces carved around the door and windows add to the beauty of the exterior."