It's mentioned in the Bible, it been used by a succession of empires and it links some of Jordan's most important historical sites.

"Welcome to Jordan!" a group of kids shouted excitedly, as I stepped out of the car to admire the sun setting over the vast sandstone canyon of Wadi Mujib.

While I stood on the cliff's edge, awestruck by the mountain ranges stretching to the Dead Sea, a black-and-white hooded wheatear swooped down near me. I wondered how something so delicate could survive in such desolate ravines, fluttering across the arid mountains and building nests in rock crevices.

From my perch, I could see a narrow, serpentine road winding down the ridges and gorges. This route, known as the King's Highway, or Darb ar-Raseef ("paved road", in Arabic), is believed to be one of the world's oldest continuously used roads. For millennia, merchants, pilgrims, warriors and kings travelled north to south through Jordan's central highlands, and this thoroughfare served as a vital artery connecting ancient kingdoms and empires.