The mountain itself was the scaffold at Petra

Nobody built Petra. Two thousand years ago the Nabataeans carved columns, ceilings, and statues — a Treasury rising about 130 feet — straight out of a Jordanian cliff, without stacking a single brick. Timber was scarce in this desert, so tall stonework had no scaffold. They flipped the job: start at the top, step down, and let the rock beneath become the next platform — the mountain itself the scaffold — then carve rooms inward under a roof of solid rock. Sources: • Universes in Universe — Khazneh — https://universes.art/en/art-destinations/jordan/petra/al-khazneh • Visit Petra — Al Khazna — https://www.visitpetra.jo/en/Location/2 • World History Encyclopedia — Kingdom of Nabatea — https://www.worldhistory.org/Kingdom_of_Nabatea/ • Wikipedia — Petra — https://en.wikipedia.org/wiki/Petra