Hamdollah Mostowfi Mausoleum, the great historian of Ilkhanid period, has a special place among Qazvin people. He is attributed to Horban Yazid Riahi and has three major books: Zafarnameh, Tarikh-e Gozide and Nehzat ol-Qolub. Because of his popularity among people of Qazvin, they built a mausoleum over his grave after his death, that is famous as Gonbaz-e Deraz or Gonbad-e Deraz which means a tall dome.
The high building of Gonbad-e Derzaz is a conical structure made of brick that have an azure blue dome. All around the building has been decorated with beautiful and delicate tiles on which the sentence has been written: “لااله الاالله الملک الحق المبین و محمد رسولالله الصادق البار الامین” “La Elaha Ela Allah ol-Malek ol-Haq ol-Mobin va Mohammad Rasul al-Allah ol-Sadeq ol-Bar ol-amin”
The building was a part of Ameneh Khatun cemetery in the past that was gradually separated and is now independently 280 square meter. But the conical building of mausoleum is itself 40 square meters. The building has two stories and in fact, its lower floor that is known as the basement, is the original mausoleum that is not visitable for the public. The upper story of this small and pleasant building has also been decorated with simple turquoise blue tiles.
The special feature of the conical dome falls it into the category of Rok Dome in the traditional architecture of Iran that includes a دوپوسته dome از هم گسسته that is melon-form from inside and conical form from outside.
One of the other features of this valuable building is using four سه کنج , فیل پوش or گوشواره that زاویه میداد the building and the skillful Iranian architects transform the square plan into octagonal, sixteen sides and thirty- two sides and finally into the circle in order to build a conical or dome building. this building has a two doors made of walnut wood on one of them the verse of Quran and on the other Insan Sura are seen. These are not the main doors of the building but the original doors were replaced by them about eighty years ago. One of the original doors was burnt in fire and the other is kept in the National Museum of Iran.
There is another inscription in the courtyard of Gonbad-e Deraz including a short description on Hamdollah Mostwofi and his works. in addition, there is a household cistern in the courtyard that is free to public visit.
This ancient building is located in Taleqani street, the former Malek Abad street, Mostowfi alley, Qazvin.