Petra was first established sometime around the 6th century BC, by the Nabataean Arabs, a nomadic tribe who settled in the area and laid the foundations of a commercial empire that extended into Syria.
The site is semi-arid, the friable sandstone which allowed the Nabataeans to carve their temples and tombs into the rock crumbling easily to sand. The color of the rock ranges from pale yellow or white through rich reds to the darker brown of more resistant rocks. The city is surrounded by towering hills of rust-colored sandstone which gave the city some natural protection against invaders.
From the entrance to the site, a dusty trail leads gently downwards along the Wadi Musa (The Valley of Moses). Once inside, the route narrows to little more than five feet in width, while the walls tower up hundreds of feet on either side. The floor of this passage is filled with all sizes of small rocks making it impossible to walk on unless you rent a horse as I did to make the long journey.
The passage way twists and turns, the high walls all but shutting out the early morning sunlight, until abruptly, through a cleft in the rock, the first glimpse of the city of Petra can be seen. Carved out of pale reddish sandstone, ornate pillars supporting a portico surmounted by a central urn and two flanking blocks jut out from the cliff face ahead. This is The Khazneh which is the best-known of the monuments at Petra. The facade, carved out from the sandstone cliff wall, is 40 feet high, and is remarkably well-preserved. The name Khazneh, which means 'treasury’, comes from the legend that it was used as a hiding place for treasure. Inside was a large square room that had been carved out of the rock of the cliff.
Surrounding the open space dominated by the Khazneh are other tombs and halls mostly little more than man-made caves carved out from the rock. A broad track from the Khazneh leads to the main street of Roman Petra, which is paved with cut stone and lined with columns. Towards the amphitheatre is an open marketplace and a nymphaeum or public fountain.
Ahead lays the centre of the city, while following the cliff face further to the right takes you north from the Khazneh to three large structures, known as the Royal Tombs that have been carved into the rock face, and is known as the King's Wall. To the north, there is one more tomb, which was built in AD 130 for the Roman governor of the city under Hadrian, Sextius Florentinus
The Temple, popularly known as the Qasr al-Bint Firaun ("The Castle of Pharaoh's Daughter"), was a large free-standing structure, built of massive blocks of yellow sandstone.
As rode out on my horse I had marveled at how the Nabataeans must have been excellent engineers. I even noticed on the return the walls of the Siq are lined with channels to carry drinking water to the city, while a dam to the right of the entrance diverted an adjoining stream through a tunnel to prevent it flooding the Siq.
And I will fill his mountains with his slain men: in thy hills, and in thy valleys, and in all thy rivers, shall they fall that are slain with the sword.  I will make thee perpetual desolations, and thy cities shall not return: and ye shall know that I am the Lord.