Jordan 1996: Petra 2
Anyone attempting to conquer Petra had to come the better part of a mile through this forbidding canyon, or siq. The Siq of course could be easily defended from above, and when you came out at the other end you could be facing an entire army of the enemy. You wouldnt want to be in the front lines of the invaders. Petra was never conquered during its many years as a haven on the spice road. Finally as its importance waned, it allowed itself to fall under the influence of outsiders.
On the back cliffs of Petra you can find tombs that look as if they were sketches for the more ornate tombs close in to the opening of the valley. In front of this tomb, the Urn Tomb, you can see arches erected in Roman manner; this tomb was converted to a Byzantine church in medieval times.
After the Romans came in and took control of Petra, they set up their own city, along more classically Roman lines, back behind the Nabatean establishment. The Roman extension includes a typical coliseum (also carved into Petras distinctive red rock), a small grid of streets and this column-lined forum, leading back toward the older city.
If you arrive early enough in the morning, you can take a day-long hike up to Jebel HarounMount Aaronrevered in Islamic custom as the resting place of Aaron. Thats a hot and thirsty hike, which we did not take.