Most likely the architecture, in certain mosques there may even be handwritten scripts which are quiet rare
The church you're referring to is now called Hagia Sophia. When Constantinople (now Istanbul) was conquered by the Turks in 1453, the Sultan ruled that the former Basilica (church) would now become a Mosque. Nowadays, it is mainly used as a museum of Byzantine artefacts.
Taking the literal meaning of 'artefacts' there must be thousands.
Artefacts - 2007 is rated/received certificates of: Portugal:M/16 USA:R
In museums
People that study artefacts are called archaeologists. However people who study fossils are known as palaeontologists.
A museum
MOSQUE
grand mosque
There is no mosque in Dubai called the F Mosque.
aretefacts?
There is no adjective to mosque. Mosque is the building where Muslims go for praying.
The lagest mosque in nigeria is kwara state mosque