Today the building is a Cathedral.
The Malwiya tower, which is the most distinguished feature in the mosque, was constructed entirely by brickwork. The use of brickwork is attributed to the Mesopotamian architects and artisans. It was constructed in the 9th century CE when the Islamic architecture was in its initial stages and was not established as it was in later centuries. The Mesopotamian architecture is evident in this monument because the early Muslims were from Arabia and the Arabs were not great architects or builders, you cannot find many notable pieces of architecture in Arabian peninsula before Islam or in the early days of Islam, this is the reason that the Arab Muslim conquerors relied solely on the Mesopotamian architecture while constructing the capital city of Samarra (which was later abandoned due to water shortage) and its monuments. Another feature of the tower Malwiya is the spiral ramp that recalls the ziggurats of Mesopotamia. The ziggurats also had the exposed staircases leading to the top of the building and same is the case with the Malwiya tower of the Great Mosque of Samarra. The ziggurat were part of temple complexes i.e. places of worship of the Mesopotamians and same is the case with the mosque as it is the place of worship of the Muslims. So it is correct to say that the Mesopotamian architecture which was the native architecture of the building is evident in the architecture of the Great Mosque of Samarra however Islamic architecture is not missing altogether. The construction involved the styles of the local culture but the architecture as a whole is distinctively Islamic because primarily the structure and the plan of the building is strictly based on Islamic structure of a mosque. An Islamic mosque is essentially supposed to have a courtyard in the centre, it is not present in the centre of the building but it is there in the mosque. Also the minaret is