A mysterious and ancient stone tunnel was recently discovered near Kibbutz Ramat Rachel in southern Jerusalem during preventative excavations ahead of the construction of the new neighborhood promoted by the Israel Land Authority (ILA).

The find, announced by the Israel Antiquities Authority (IAA) on Thursday morning, is expected to measure approximately 50 meters long, 5 meters high, and 3 meters wide.

“We were excavating in relatively rocky and exposed terrain when suddenly we discovered a natural karstic cavity,” said Dr. Sivan Mizrahi and Zinovi Matskevich, excavation directors on behalf of the IAA. “To our amazement, as the excavation progressed, this cavity developed into a long tunnel. Parts of it are still collapsed, so the tunnel has not yet revealed all of its secrets.”

After descending a set of ancient stairs from the surface, archaeologists found themselves standing at the hewn opening of the tunnel, which was filled with sewage that had apparently flowed into it over hundreds or thousands of years.

“The quarrying was executed meticulously. It is clear that whoever carved this tunnel invested tremendous effort, careful planning, and possessed the capabilities and resources necessary to achieve this goal,” Mizrahi and Matskevich said.

The age of the tunnel is also a mystery to researchers, the excavation directors explained, “since not even the smallest find was uncovered that could indicate when it was created.”

Even so, the two noted that the tunnel is only a few hundred meters from two other important historical sites: an Iron Age (First Temple period) public building in Jerusalem’s Arnona neighborhood and Tel Ramat Rachel, which is home to settlement remains from both the Iron Age and the Islamic period. 

Yet the purpose of the tunnel remains unclear.

Initially, researchers proposed that the tunnel was an ancient water installation built to reach a nearby spring.

This assumption, however, was ruled out for several reasons: The lack of plastering on the tunnel walls, a common practice for water infrastructure in order to prevent seepage; following a consultation with a geologist, who explained that there are no known underground water sources in the surrounding area; and because the tunnel bears no indication of water accumulation.

The second possibility floated by researchers was that the tunnel belonged to an underground agricultural or industrial installation. However, upon further examination, the scale of the work and the absence of comparable sites in the vicinity made this explanation unlikely.

Currently, the assessment is that the tunnel was dug to reach a chalk layer suitable for quarrying building stone or for lime production. A possible ventilation shaft carved into the tunnel’s ceiling, as well as quarrying debris discovered on the tunnel’s floor, support this theory, although it too remains uncertain.

Alternatively, the tunnel may never have been completed, leaving its intended purpose and nature unknown.

Dr. Amit Re’em, a Jerusalem District archaeologist at the IAA, added that the discovery, on the eve of Jerusalem Day, joins many others “being uncovered every day, hour by hour, throughout the city.”

“Usually we have explanations for the discoveries we uncover, but sometimes, as in this case, we stand astonished and amazed,” Re’em said.

Heritage Minister Amichai Eliyahu echoed the sentiment, noting that “during Jerusalem Day week, this special discovery reminds us of the deep and ancient connection of the Jewish people to Jerusalem.”

“Beneath the city’s soil, extraordinary enterprises of life, creativity, and construction are revealed time and again, testifying to generations of people who lived and worked here and left their mark,” he said. “Jerusalem is not only the present-day capital of the State of Israel - it is also the heart of the historical story of the Jewish people, which continues to be uncovered before our eyes.”

The tunnel is expected to be incorporated into a public archaeological park built near the new neighborhood being planned by the Israel Lands Authority.

The neighborhood, to be built north of the kibbutz on approximately 58 dunams, is expected to include 488 housing units, thousands of square meters designated for employment and commercial use, an elementary school, and kindergartens.