Istanbul

Byzantium was an early Earth city that later came to be known as Constantinople and Istanbul. It became part of the Roman Empire.

The Torchwood Institute believed that the sewers of fourth century Byzantium had a Weevil population. (WEB: torchwood.org.uk)

The Doctor visited the city in his first incarnation in 64 AD.

Other uses of the name
By the 27th century a city of New Byzantium existed on the human colony world of Tairngire. (NA: Shadowmind)

At some point in the future, probably the 61st century, a New Byzantine Calendar was in use. (DW: The Doctor's Daughter)

The Byzantium was a spacecraft in the 51st century that was transporting a Weeping Angel; it crashed on Alfava Metraxis when its warp engines suffered a phase shift. (DW: The Time of Angels)