Archaeologists hoping to find Cleopatra's lost tomb have instead discovered an incredible feat of engineering: a 6.5-foot-tall underground tunnel stretching for nearly a mile. The Egyptian Ministry of Tourism calls it a "geometric miracle," per Smithsonian. Kathleen Martinez of the University of San Domingo, whose team uncovered the tunnel cut into rock more than 40 feet beneath the ruins of the temple of Taposiris Magna near Alexandria, tells Live Science it's "an exact replica of Eupalinos Tunnel in Greece, which is considered as one of the most important engineering achievements of antiquity." That tunnel on the Greek island of Samos, built centuries before Taposiris Magna, served as an aqueduct for 1,000 years, per Smithsonian.
It's believed this tunnel carried water as well. Parts of it are now flooded by the Mediterranean Sea, likely as a result of at least 23 earthquakes that hit the region between AD 320 and 1303, per the Times of Israel. Those same earthquakes may have brought down the temple above, dedicated to the god of the underworld, Osiris. Its destruction has complicated efforts to search for the tomb of Egypt's Queen Cleopatra VII and her lover, Roman general Marc Antony, who committed suicide in 30 BC, at the end of the period to which the tunnel dates, per Live Science. Though other experts disagree, Martinez believes the couple's tomb might be found at the site. Previous excavations uncovered coins bearing Cleopatra's likeness.
Archaeologists also found a cemetery of mummies facing in the direction of the temple, which Martinez says could be a sign of a royal tomb nearby, per the Times. She notes some mummies were given golden tongues, which were thought to allow the dead to speak with Osiris. Martinez hopes the tunnel might lead her to the tomb and "the most important discovery of the 21st century," per the Times. "This is the first time that any archeologist has found tunnels, passages underground [and] inside the enclosure walls of the temple," she tells the outlet. But researchers note the tunnel itself is impressive. It's believed to have been built to carry water to the city of Taposiris Magna at a time when it counted 15,000 to 20,000 inhabitants. (More discoveries stories.)