Sasanian architecture refers to the Persian architectural style that culminated in its development during the Sasanian era. In many ways, the period of the Sasanian Empire (224 – 651 C.E.) saw the highest achievement of Iranian civilization and restored much of the greatness of the Persian Empire as a successor of the Achaemenid Empire. Sasanian art revived forms and traditions that originated in Persia and showed amazing vigor and not just an imitation of the Achaemenid past. The splendor with which the Sasanian monarchs once lived is well illustrated by their surviving palaces, such as those at Firouzabad and Bishapur in Fars, and the capital Ctesiphon in modern Iraq. In addition to local traditions, Parthian dynastic architecture is also responsible for a large number of Sasanian architectural features. All are characterized by barrel or tunnel-vaulted iwans introduced in Parthian times, but have now reached great proportions, especially at Ctesiphon. The Persians solved the problem of building a round dome over a square building by the squinch. It is an arch built at each corner of the square, so turning it into an octagon on which the dome can be placed very simply. The height of the arch varies in Sassanid constructions from about 50 to 85 feet; it is usually simple and unadorned. The domed apartments are squares of from 25 to 40 feet, or a little more. The Sassanids' exterior decorations range from the ground to the cornice, while between them are a series of tall narrow double recessed arches. The unique feature of Sasanian architecture is its distinctive use of space. Sassanid Architects designed its building in terms of volume and surfaces; hence the use of large brick walls decorated with stucco moldings. (Credit: Sasanian_architecture , Wiki) [image1. Deir-e Gachin Caravanserai, constructed by Ardashir I in 240 AD 2. Shushtar Historical Hydraulic System 3. Falak-ol-Aflak, Khorramabad, Lorestan, Iran 4. Rayen Castle]