Soheil Nazari and Amirhossein Mahmoudnejad 451 Documentation and Analysis of The Free-Handed Vaulting Technique at The Toor Caravanserai, Iran Soheil Nazari [1], Amirhossein Mahmoudnejad [2] [1] Brandenburgische Technische Universität Cottbus – Senftenberg, Cottbus, Germany DFG Graduiertenkolleg. [2] University of Tehran, Faculty of Fine Arts. Abstract The article intends to document a neglected Caravanserai in Iran. The caravanserai is of early sixteenth century construction, a period that witnessed an evolutionary movement in road construction projects promoted by Safavids. The building is located on a previously significant road between Isfahan and Golpayegan. As a result of decades of neglects, portions of the vault infill have collapsed allowing investigation of the vaulting technique. The vaults are constructed based on free-handed technique without using centering or formwork. The analysis of this kind of vaulting has been rarely mentioned in scholarly sources. This article gives a detailed description of the material used in the construction and documents the technique of the vaulting. The vaults have been surveyed by photogrammetry, allowing use to obtain 3D model of the vaults with the actual characteristics of bricks, and geometry of the vaults. Introduction The Toor Carvanserai is located on the western edge of the Iranian desert Dasht-e Kavir, between latitude 33º12'39" and longitude 50º44'25", on a historic main road leading to Isfahan, and was built in the early stages of the road construction projects promoted by the Safavids dynasty (1501–1736 AD). It was an established policy of the Safavids to stage the roads that were connected with caravanserais. Primary sources put the building on the historical map of the Isfahan– Golpayegan road, a strategic highway between two historically well-known urban districts. A caravanserai was a roadside inn where travellers (caravaners) could rest and recover from the day's journey. Toor Caravanserai is first mentioned in Jean Chardin’s (1643–1713 AD) travelogue [1], and was later noted by Maxime Siroux, who collected a general information on the locations and histories of Iranian caravanserais and ancient routes in the twentieth century [2]. As trade routes developed in the Safavids era, caravanserais became more of a necessity. This resulted in a network of caravanserais that stretched from east to west, connecting important cities like Herat in the east and Mashhad in the north- east to Isfahan, and from there to Sari and Rey in the north, and Tabriz in north-west. A caravanserai is a roadside inn where people travelling in groups across the dessert on camels could rest after a day’s journey, particularly to ensure safety when travelling through a dangerous area. Caravanserais constitute the second largest group of buildings, after mosques, in the architectural heritage of Iran. A wide variety of architectural designs and vaulting techniques can be traced in caravanserai construction in different climates zones of Iran. Since caravanserais were constructed mostly far from the cities in the middle of deserts, architects adopted the simplest and most durable methods of construction. The construction materials of caravanserais were generally chosen according to local resources. In the Toor caravanserai fired bricks are employed in the vaulted coverings and the walls, supported by travertine stone in the plinths. The vaulting technique is associated with free-handed vaulting [3] without formwork. This technique, frequently used in central Iranian architecture, allows construction beyond the constraints of timber or gypsum consumption as formwork. The technique is applicable to both ordinary building tasks and complex geometry as well as