Al-Khazneh

Where it sits. Al-Khazneh stands at the point where the Siq, the fault-split gorge that forms Petra's main entrance, opens into a small forecourt in the Wadi Musa basin of southern Jordan. It is carved directly into the eastern wall of the Jebel al-Khubtha massif, facing roughly west-north-west, which is why it stays in shadow through the morning and takes reflected glow rather than direct sun for most of the day. The facade measures about 39 metres high and 25 metres wide, cut top-down into a single sheet of rose and cream Umm Ishrin sandstone. The name means the Treasury, and it is a misnomer supplied by local tradition, which held that an Egyptian pharaoh had hidden gold in the urn crowning the upper storey. Generations of gunfire aimed at that urn have chipped it badly; it is solid rock and always was.

What it actually is. Scholarly consensus treats Al-Khazneh as a royal tomb, most often assigned to Aretas IV, who ruled the Nabataean kingdom from 9 BC to AD 40, though earlier attributions to Aretas III and later Roman-period datings have all had defenders. Excavation beneath the forecourt in the early 2000s uncovered a lower level of tombs, showing that the visible facade sits above further burials and that the original ground surface was several metres down. The architecture is a hybrid that only makes sense on a trade frontier: a Hellenistic lower order of six Corinthian columns and a broken pediment above, then an upper storey split around a central tholos, all of it Alexandrian in vocabulary but executed by Nabataean masons who worked from scaffolding cut as they descended. The carved figures include Isis-Tyche on the tholos and, on the upper flanks, Amazons and Dioscuri weathered nearly to outlines. Behind the doorway the interior is anticlimactic by design: a bare square chamber roughly 12 metres on a side, with two smaller side rooms and no decoration whatsoever.

On screen. This is one of the most recognised buildings in cinema, and almost everything audiences believe about it is wrong. Steven Spielberg used the facade for the exterior of the Grail temple in Indiana Jones and the Last Crusade, shot in Jordan in 1988 for a 1989 release, with the ride down the Siq framed so the facade arrives in a slot of light. The moment Harrison Ford steps through the door the film cuts to Elstree Studios outside London, where the three trials, the pillared cavern, the knight and the collapse were all built as sets. Visitors regularly arrive expecting an interior and find an empty room they are no longer allowed to enter at all, since access was closed for conservation. The facade had already appeared in Sinbad and the Eye of the Tiger (1977), and it turns up again in Mortal Kombat: Annihilation (1997) and in Transformers: Revenge of the Fallen (2009), where Michael Bay's plot treats it as a short walk from the Giza pyramids — a thousand kilometres and a national border removed from the truth. It has since become a fixture of travel television and video games, from An Idiot Abroad to the original Assassin's Creed.

What you actually see today. The forecourt is now managed with rope lines that keep visitors back from the lower order, and the sand surface has been consolidated. Bedouin stalls sell tea and jewellery along the northern edge, and camels are stationed for photographs. Look for the water channel that runs along the Siq wall at chest height on the right and terminates near the entrance, the drill holes and toe-holds left by the original carvers on the upper cornice, and the erosion undercutting the base of the left-hand columns, which is the reason for the ongoing structural monitoring by Jordanian and international conservation teams. The best elevated view is from the ledge on Al-Khubtha reached by a stepped trail of about 600 steps starting near the Royal Tombs, which puts you level with the urn.

Getting there and timing. It is a walk of roughly 2 kilometres from the Petra visitor centre in Wadi Musa: 800 metres of open valley, then 1,200 metres of gorge. Allow 30 to 40 minutes at a normal pace. The gorge floor is mostly compacted gravel with some Roman paving and is negotiable with assistance, though the gradient is continuous. Arrive at opening for an empty forecourt; by nine the space in front of the facade is dense with groups, and it stays that way until late afternoon. Petra by Night lights the forecourt with candle bags on selected evenings, and it is the only time the building is seen without daylight competing.