Sar-e Qabr-e Āqā mausoleum was built in the 13th century AH/AD 19th century, simultaneous with the reign of Nāsser-ad-Din Shāh Qājār, in an old cemetery near the gate of Shāh-Abdolazim, Ray, as a burial place for Seyyed Abolqāsem Zahir-ol-Eslām, the Friday Imam (prayer leader) of Tehran. With four iwans, along with a double-covered high dome and other various and exquisite decorations in combination with a triangular pediment of the main iwan and the Corinthian capitals as well as other Western decorations adapted from European architecture during the Nāsser-ad-Din Shāh’s reign, the mausoleum is considered a unique example of this style of architecture, i.e. religious and monumental. It should be noted that the Basilica of the Sacred Heart of Paris, commonly known as Sacré-Cœur Basilica and often simply Sacré-Cœur, Paris (1914), which seems to have been much seen and admired with a good reputation in Tehran, has affected the form and construction of this dome. Being in the form of a rectangular cube along its east-west longitude, the mausoleum is located on a platform approximately one meter above the level of the adjacent area.   
The present research has been carried out with the aim of studying architectural features and decorations of the Sar-e Qabr-e Āqā mausoleum. In this writing, with a descriptive-analytical methodology and by relying on historical documents and registration files of ICHHTO, together with field studies and documentation of the mausoleum through map preparation and photography, the architecture and decorations of the tomb were introduced, and by library studies based on the interpretive-historical method, the history of the mausoleum and the historical reasons for the influence of Western architectural elements on the architecture of Sar-e Qabr-e Āqā mausoleum have been examined.   
The plan, structure, and decorations of the building resemble those of the mausoleums of Tehran's shrines during the Qajar period, such as the Hazrat-e Abdolazim Shrine. The Sar-e Qabr-e Āqā mausoleum with its wide entrance iwan along with the triangular pediment, exquisite mirror-work inside the dome house, stuccowork, tiles, and exquisite wooden shrine of the tomb, has been inspired by the Imāmzādeh mausoleums (shrines of Imams’ descendants) of the Qajar period. This place has the only triangular pediment above the entrance iwan in a Qajar religious building in Tehran. Most religious structures such as the tomb of Shah Abdolazim in Ray and Imāmzādeh Sāleh in Tajrish had a pediment in their entrance iwans, but throughout history, many of these triangular pediments have transformed into circular or flat patterns. The Sar-e Qabr-e Āqā mausoleum could be considered as the only Qajar tomb remained with a triangular pediment.
Considering the style of architecture in Sar-e Qabr-e Āqā mausoleum and that of the shrines of Tehran during the Qajar period, the results show that the architecture and exquisite decorations of the tomb as well as the use of European architectural elements in combination with Iranian tomb architecture in here were to strengthen the spiritual and the powerful status of Tehran's Friday Imam and his family, and on the other hand, is a manifestation of modernity in the architecture of Iran in this period, i.e. the 13th century AH/ AD 19th century.