Halabiye
This site, on the right bank of the mid Euphrates River, is approximately 100 km south of Al Raqqa and 66 km north of Deir Ezzor. Having been one of the most fortified of Byzantine defensive projects it is now a beautifully preserved site. 

The site of Halabiye was first built when the kingdom of Palmyra took over the area in 266 AD. Under Zenobia it was fortified as a defensive structure to guard Palmyrean control on the Euphrates valley. However, the Romans, in retaliation to Zenobia's rebellion, took it over when they occupied Palmyra.

Under the Romans it was rebuilt and fortified twice, once under Diocletian in an effort to strengthen his defenses in this area. The other period of expansion was under the Byzantine Emperor Justinian (527 - 565), in an effort to fortify this city against Persian threat. 

In 610 AD the Sassanian Persians occupied most of Syria, sacking Halabiye on their way. Later on about 15 years later the Arabs took over most of the east and as the Euphrates was no longer a frontier for them, Halabiye was of little use and it was abandoned forever.

What is left now of Halabiye is a complex plan of ruins including a number of tower tombs on the riverside, the cardo maximus, some baths, 2 basilicas, and a forum. The walls to this city are quite well preserved and are interrupted by towers every few meters. Furthest away from the river is a praetorium which was soldiers' barracks, and a citadel which was originally Byzantine but was rebuilt and altered by the Arabs.

Zalabiye
Halabiye's twin city is that of Zalabiye which is located 2 km downstream on the opposite side of the Euphrates. Zalabiye shares all of Halabiye's steps through history. 

Zalabiye comprises of a plan similar to Halabiye although it is in a less preserved state, only the east side remains.

It is difficult to get to Zalabiye, there are no bridges on the Euphrates here, the closest is in Deir Ezzor.