This relic is from the Saljuqi period. The actual grave is on a lower level than its surrounding.
The ‘Haram’ or Imamzadeh has lost some of its ancient charm. The entrance of this mausoleum faces east, and its two halls are adorned with tile work from the Safavid and Qajar periods.
The intricate carvings on the doors and around the fringes are the masterpieces of the craftsmen of the Safavid era. Internally the Haram is octagonal with a wooden and silver railing in the center.
This structure was constructed in the year 1203 AH. There is a belief that this is the resting abode of one of the offspring of Imam Mousa Kazem, though the actual name of the person buried is Abdollah-ebn-al-Hossain-al-Ma’quf ebn-al-Hossain.
Source: Travital