A mystery more staggering than Egypt’s pyramids: colossal stone blocks weighing 1,650 tons each, defying all logic.

A team of German and Lebanese archeologists just uncovered the largest manmade stone block ever discovered.

The block, which was found in a limestone quarry in Baalbek, Lebanon, measures 64 feet by 19.6 feet by 18 feet, Gizmodo reports and weighs an estimated 1,650 tons.

Other massive manmade blocks were previously found nearby, including one weighing up to 1,240 tons and nicknamed “The Stone of the Pregnant Woman.”

The blocks likely date back at least 2,000 years, to around 27 BC. At the time, Discovery writes, Baalbek was a premier outpost of the Roman empire and went by the name Heliopolis—“the city of the sun.”

The German Archeological Institute reports that the block was probably intended for use in a nearby temple for the god Jupiter.

This stone and others, however, never made it out of the quarry, probably because they turned out to be much too massive to transport, the Institute reports. Indeed, a crack had already formed in one corner of the Stone of the Pregnant Woman.

Even though the block was likely a major disappointment to its creators, they unwittingly set world records.

The newly discovered block, the Institute writes, is “the biggest boulder known from antiquity.”