Mysterious 2,800 Year Old Structures Found in Old Jerusalem Baffle Experts

Two "unique" ancient structures found in Jerusalem—the purpose of which remains a mystery—are baffling experts, according to the Israel Antiquities Authority (IAA).

The recently discovered network of channels carved into rock is thought to be almost 3,000 years old. The installations are the first of their kind ever discovered in Israel, the IAA said in an announcement Wednesday.

The structures were in use when the city's First Temple was thought to have existed, researchers said.

The central location of the channels near the site of the Temple and royal palace during the era of the ancient Judean kings indicates that the installations had some connection to the economy of these prominent institutions.

Excavations conducted by the IAA and Tel Aviv University in the City of David National Park have so far uncovered two installations just over 30 feet apart, which may have been part of one large installation.

"The mystery only grew deeper when we found the second installation to the south," Yuval Gadot of Tel Aviv University's Archeology and Ancient Near Eastern Civilizations Department said in a statement.

The national park in which the structures were found contains the City of David archaeological site—considered by most scholars to be the location of the original settlement at Jerusalem.

"We looked at the installation and realized that we had stumbled on something unique, but since we had never seen a structure like this in Israel, we didn't know how to interpret it," Yiftah Shalev, a senior researcher at the IAA, said in a statement. "Even its date was unclear."

"We brought a number of experts to the site to see if there were any residues in the soil or rock that are not visible with the naked eye, and to help us understand what flowed or stood in the channels. We wanted to check whether there were any organic remains or traces of blood, so we even recruited the help of the police forensic unit and its research colleagues around the world, but so far—to no avail," Shalev said.

Despite some differences in the way the two channels were hewn and designed, it is clear that both are quite similar, the IAA said.

Researchers have managed to date when the installations fell out of use—at the end of the 9th century B.C. during the days of the biblical Judean kings Joash and Amaziah.

"We assume that the two installations, which, as mentioned, may have been used in unison, were constructed several decades earlier," Gadot said.

While the purpose of the structures is not yet clear, it is possible—at least in the case of the northern installation—that they were used to soak some type of product, not to drain liquids, Shalev said.

"The production of linen, for example, requires soaking the flax for a long time to soften it. Another possibility is that the channels held dates that were left out to be heated by the sun to produce silan [a type of date honey], like similarly shaped installations discovered in distant places such as Oman, Bahrain and Iran," Shalev said.

The researcher said that in the near future, archaeologists will take additional soil samples from the installations in an attempt—once again—to uncover evidence that may help to solve the mystery of what the seemingly important product was.