In Petra, the Way In Is a Crack in the Rock

This episode is one walk through the Siq at Petra, in southern Jordan: a kilometre of gorge that narrows to three metres, rock walls rising close to two hundred metres over your head, and the Treasury of Al-Khazneh standing at the far end where the cleft finally opens.

Petra is an ancient city in Ma'an Governorate, southern Jordan, at about 810 m. UNESCO describes it as "half-built, half-carved into the rock", surrounded by mountains "riddled with passages and gorges", and calls it "one of the most precious cultural properties of man's cultural heritage". The site was inscribed as a World Heritage Site in 1985. 1

The Siq is the main entrance to the city from the east, and it is a natural geological fault: the rock was split apart by tectonic forces and only later worn smooth by water, which is the opposite of a slot canyon, where moving water does the cutting. The gorge winds about 1.2 km, is no more than 3 metres wide at some points, and its walls stand between 91 and 182 metres high. Along both walls are votive niches holding baetyli, and in 1998 digging to lower the road uncovered near-life-size statues of two merchants, each leading two camels. An arch that once stood over the entrance collapsed in an earthquake in 1896. 2

At the mouth of the Siq there is a dam built to bar the gorge and reroute the flood water of Wadi Musa; the one standing there now was reconstructed in 1963 and again in 1991, and is a fairly true reconstruction of what the Nabataeans did between the 1st century BC and the beginning of the 1st century AD. Channels were cut along the walls, and UNESCO lists the diversion dam, the Muthlim tunnel, water channels, aqueducts, reservoirs and cisterns as outstanding water engineering of the first centuries BC to AD — an ingenious system, in UNESCO's words, that "allowed extensive settlement of an essentially arid area". The Nabataeans settled here in the 4th century BC and made Petra the capital of their kingdom in the 2nd century BC; the city's population peaked at an estimated 20,000 people in the 1st century AD. Petra stayed unknown to the western world until the Swiss traveller Johann Ludwig Burckhardt reached it in 1812. 123

At the end of the walk stands Al-Khazneh, the Treasury: a rock-cut mausoleum 25.3 m wide and 39.1 m high, probably built early in the 1st century AD during the reign of the Nabataean king Aretas IV Philopatris. There is very little behind the facade — the interior is a plain main chamber and three antechambers, about 2,000 m³ in all. The name comes from a Bedouin belief that the stone urn high on the upper level held treasure; the urn is solid sandstone. 4

Visual credits: all footage and photographs in this episode come from the royalty-free pools and are free for commercial use with no attribution required. The walk into the Siq is Pexels video 5; the rock-cut tomb facades are Pexels video 6; the Treasury standing at the end of the Siq is Pixabay video 7; the close view of its carved facade is Pexels video 8; the banded sandstone close-up is a Pexels photograph 9; and the cover photograph is a Pexels photograph 10.