") was a fortified road

Roman road

The Roman roads were a vital part of the development of the Roman state, from about 500 BC through the expansion during the Roman Republic and the Roman Empire. Roman roads enabled the Romans to move armies and trade goods and to communicate. The Roman road system spanned more than 400,000 km...

 that ran along the eastern desert border, the limes Arabicus

Limes Arabicus

The Limes Arabicus was a desert frontier of the Roman Empire, in the province of Arabia Petraea. It ran -at its biggest extension- for about 1,500 km, from Northern Syria to Southern Palestine and northern Arabia, forming part of the wider Roman limes system...

, of the Roman Empire

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

. As its name suggests, it was constructed under Emperor Diocletian (r. 284–305) as part of a wide-ranging fortification drive in the later Roman Empire. The strata was lined with a series of similarly-built rectangular forts (quadriburgia) situated at one day's march (ca. 20 Roman miles) from each other. It began at the southern bank of the river Euphrates

Euphrates

The Euphrates is the longest and one of the most historically important rivers of Western Asia. Together with the Tigris, it is one of the two defining rivers of Mesopotamia...

 and stretched south and west, passing east of Palmyra

Palmyra

Palmyra was an ancient city in Syria. In the age of antiquity, it was an important city of central Syria, located in an oasis 215 km northeast of Damascus and 180 km southwest of the Euphrates at Deir ez-Zor. It had long been a vital caravan city for travellers crossing the Syrian desert...

 and Damascus

Damascus

Damascus , commonly known in Syria as Al Sham , and as the City of Jasmine , is the capital and the second largest city of Syria after Aleppo, both are part of the country's 14 governorates. In addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major...

down to northeast Arabia.