What is the Roman road in Jordan , southwest Asia made out of ?

Answer

An example of this is found on the Roman road from Căzănești near the Iron Gates. This road was half carved into the rock, about 5 ft to 5 ft 9 in (1.5 to 1.75 m), the rest of the road, above the Danube, was made from wooden structure, projecting out of the cliff. The road functioned as a towpath, making the Danube navigable.