Note 532 — BOOK VI. AN ACCOUNT OF COUNTRIES, NATIONS, SEAS, TOWNS, HAVENS, MOUNTAINS, RIVERS, DISTANCES, AND PEOPLES WHO NOW EXIST, OR FORMERLY EXISTED.
John Bostock translation
The city of Seleucia ad Tigrin, long the capital of Western Asia, until it was eclipsed by Ctesiphon. Its site has been a matter of considerable discussion, but the most probable opinion is, that it stood on the western bank of the Tigris, to the north of its junction with the royal canal (probably the river Chobar above mentioned), opposite to the mouth of the river Delas or Silla (now Diala), and to the spot where Ctesiphon was afterwards built by the Parthians. It stood a little to the south of the modern city of Baghdad; thus commanding the navigation of the Tigris and Euphrates, and the whole plain formed by those two rivers.