The gate-way has been made of brick and stands to an elevation of over 7 m.
The ceiling of the chambers resemble a barrel, but the main rooms have ceilings covered with shallow domes. The master-piece of this structure is the door way, worked with pieces of seven-colored tiles depicting a scene from the myth of Shahnameh's Rostam and the white monster.
The inscriptions of the above mentioned structure are the works of the famous personality of Semnan, by the name of Seyed Mohammad Baqer Tabatabaie Semnani.
The doors of the gate-way are of thick planks of wood studded with iron spikes. After the 1979 Islamic Revolution, this monument was repaired by the Cultural Heritage Organization of the province.
Source: Tourism of Persia