Hagia Sophia

The church of Panagia Acheroizitis is an extremely well preserved paleochristian basilica. Built in the fifth century on Roman baths, this church was the first to be converted into a mosque around 1430 under the name "Eski Camii" and was used as such until 1930. It is a World Heritage Site. Since 1988

The church of Panagia Chalkeon, often called "red church", is a Byzantine church built in the 11th century on an old pagan house of worship. Two events affected the church in the twentieth century: a fire in 1917 and an earthquake in 1932, which caused considerable damage and led to the restoration of the Panagia Chalkeon. It is now a UNESCO World Heritage Site as a Byzantine monument in Thessaloniki.

The Arch of Galerius and its nearby Rotunda, are ancient monuments built in the early fourth century. The complex to which they belonged was built during the reign of Emperor Galerius (305-311). During its existence, the Rotunda was used as a pagan temple (early fourth century), a church (late fourth century-1590/1912-), a mosque (1590-1912). It is a UNESCO World Heritage Site since 1988.