This may look like a modern civil engineering marvel—but in fact you're looking at the largest known stone block to be tirelessly carved by ancient human hands.
Discovered in a stone quarry in Baalbek, Lebanon, by German archaeologists, the perfectly hewn chunk of stone measures 19.5 metres by 5.9 metres and is 5.4 metres tall. It's estimated to weigh 1,650 tonnes, making it — according to the researchers — the "biggest stone block from antiquity". The German Archaeological Institute explains:
"The level of smoothness indicate the block was meant to be transported and used without being cut... [But] it would have probably cracked during transportation."
Indeed, other large stone blocks, all smaller than this one, were found nearby—notably one weighting about 1,240 tonnes, some of which show signs of damage. That suggests that some were moved, but then the plan abandoned when it was discovered they were too big to transport in safety.
It's believed the stones date back over 2,000 years to at least 27 BC, and that they were due to be used in one of several major temples under construction at the time. [Deutsches Archäologisches Institut via Discovery]
Image by Deutsches Archäologisches Institut.