There were many stone movers in the ancient world. From Stonehenge to Macchu Picchu, ancient peoples found a way to move stones of massive proportions. The Olmec of Central America moved enormous stone heads, possibly by floating them down rivers on rafts. The Inca created mountaintop kingdoms out of enormous yet intricately fitted stones, each dragged for dozens of miles. Easter Islanders carved and moved some of the largest stone sculptures ever created.

The largest hewn stone yet discovered, however, was not found in any of these places, but in the Lebanese town of Baalbeck, in the ruins of a city once known as Heliopolis, “the City of the Sun.”

In the base of the ruins of the Jupiter Baal Temple lie three hewn stones known together as the “trilithon.” Each is estimated to weigh over 750 tons. Construction on the massive Roman temple of Jupiter began roughly 27 years before the birth of Jesus, and while most scholars agree the blocks were cut by the Romans, there is some evidence that the trilithon may predate their presence in the Middle East. In fact, the stones may predate even Alexander the Great, who founded Heliopolis in 334 B.C.

Whether Roman masons or some other group, someone devised a way to move these massive blocks from the quarry over many miles and to then lift them onto a base of smaller blocks. In addition to the trilithon, there is a fourth stone in the temple, the largest of them all—indeed, the largest stone ever hewn by man.

Known as the “Stone of the Pregnant Woman,” it weighs an estimated 1,200 tons—equivalent to three Boeing 747s. This massive weight apparently proved too much for anyone to move, and the stone was left in the place where it was cut, an enormous rectangle sticking up at an angle from the ground.

How Roman architects (or whoever it was that moved the trilithon) ever thought they would move such an enormous block remains a source of much debate.

The Atlas Obscura Podcast is a short, daily celebration of all the world’s strange and wondrous places. Check out this episode about the Baalbek Trilithon.