The Stone of the Pregnant Woman, an unmoved ~1,000-tonne monolith still lying in the Baalbek quarry · Wikimedia Commons

Baalbek Quarry

Heliopolis

QuarrySyria · Baalbek, Bekaa Valley, LebanonBuilt 16 BCE · Destroyed 300 CE

About

Three stone blocks weighing roughly 800 tons each still sit in this Bekaa Valley quarry, cut for the podium of the Temple of Jupiter but never moved the final few hundred meters to the sanctuary. The largest uncarved stone recorded anywhere in antiquity lies here too, over 1,000 tons of solid limestone. Construction of Heliopolis's great sanctuary complex had been underway since the reign of Augustus, and by 117 CE the quarry had already supplied a century of monumental building.

What happened here

The rock is worked in benches from the top down, so that gravity does the moving. Channels are cut around a block with a pick, then it is split from the bed with iron wedges driven into a line of holes, sometimes with wooden wedges soaked to swell. Blocks are dressed roughly on the spot — no one hauls waste — and marked with the quarry, the gang, the date and the consular year, which is how the empire keeps track of what it owns. Sledges, rollers and ox teams take them to a river or the sea, because moving stone overland is the expensive part. Fine marbles are imperial monopolies. Abandoned faces still show the last unfinished cut, stopped mid-job and never resumed.

In ancient writing

Macrobius, Saturnalia 1.23
Records that the oracle of Jupiter Heliopolitanus at Heliopolis (Baalbek) predicted in 114 CE that Trajan would not return from his Parthian campaign.