Reconstruction of the Dome of Seh-Gonbad TombTower in Urmia Based on Architectural Documents

Seh-Gonbad tomb tower is a Seljuq monument in Iran that despite its peculiar features has received littlescholarly attention. Geometric decorations, Kufic inscriptions, along other architectural features have made this tower one of the significant funerary examples of sixth-century architecture. While the rich decorations and inscriptions of this building have been studied earlier, there is little information regarding its architectural characteristics. Given that some of the architectural elements of tomb towers such as this have changed over the years due to neglect, the question in this research is: What were the architectural characteristics of the exterior dome of this tomb tower? The aim of thispaper is to investigate the physical structure of the Seh-Gonbad, focusing on its formal, geometric, and proportional features in order to reconstruct the destroyed part of the building (thedome). Field and library research were used in this paper as well as acomparative analysis with contemporaneous andsimilar examples. Through comparative analysis with other tomb towers in the region,the research sheds new light on the geometric proportions of the Seh-Gonbad which introduces a novel geometric system in these monuments and theirexterior features. Finally, it is concluded that based on physical transformations in the Seh-Gonbad tower over time and its architectural and geometric similarities with parallel examples, this building had an external dome in the past,most likely conical or pyramidal in shape.