The Imamzada Nur, or Emamzadeh Nour, located in the Sarcheshmeh quarter of Gorgan in Golestan province, is the tomb of Eshagh Ibn Mousa Ibn Jaafar, the brother of Emam Reza (the eighth Shiite saint), whose mausoleum complex is located in Mashhad. As the building has undergone many poor restorations, It is difficult to estimate the exact year of construction for this building. One mihrab appears to be Seljuk, and others Ilkhanid; these were likely later additions. The building is very similar to the tower of Mihmandoust in that both are flanged and both are dodecagonal. Previously, the ground level of the imamzadeh was higher than that of its neighboring buildings. Today, it stands alone near a water reservoir; its former neighbors have been demolished.
The tomb is a twelve-sided polygon, entered on the southeast. Two other entrances on its southwest and northeast are now closed. It rests on two superimposed stepped plinths. The flanges begin at the level of the upper plinth, a half meter above ground level. These flanges merge into a corbelled cornice, and the tomb is covered with a metal roof with a lantern on top. Earlier roof(s) were probably wooden, and covered the structure at the same height. Within, the interior is almost rectangular; it measures 6.9 by 9.8 meters, and is aligned northeast-southwest.
On the exterior, nine of its twelve sides (except the northeast, southeast, and southwest) are decorated with large brick panels. Very likely, the northeastern side had also had a brick panel that no longer exists. These panels are remarkable in their very complex Kufic patterns. No other Seljuk building in the Caspian Sea area displays such complexity of ornamentation. The panels have been somewhat altered by restorations.
The southwest side, which was the original entrance, is the only side that does not have an upper panel in high relief. However, it has a large panel of glazed tilework above the archway, forming a ten-pointed star. The side walls of the archway are ornamented with a shallow muqarnas niche. This is repeated on the northeastern side of the tomb, which probably was intended as a second or substitute entrance. The date 867 AH (1462 CE), possibly referring to a renovation, is marked on the brickwork.
On the interior, the mihrab displays the only remaining medieval decoration. Made of stucco, it is fully decorated with floral carvings and a Kufic Quranic inscription along the top of the arch. Over the mihrab is a stucco plaque. A set of two carved wooden doors lead to the interior. The cenotaph is made of stucco and is covered by a wooden box, decorated with Kufic carvings, indicating that Emam-zadeh Ishagh was a child of the seventh Shiite saint.
Sources:
Hillenbrand, Robert. 1987. "Saljuk Monuments in Iran V: The Imamzada Nur, Gurgan." Iran: Journal of the British Institute of Persian Studies, XXV, 55-76.
Sotudeh, Manuchehr. Az Astara Ta Astarabad. Volume 5. 1987-88. Tehran: Vizarat-i Farhang va Irshad-i Islami, Idarah-'i Kull-i Intisharat va Tablighat, 196-199.