Jerusalem Tunnel Linked to Bible

Stefan Lovgren
for National Geographic News
September 11, 2003
Researchers using sophisticated radio-dating techniques have concluded that a tunnel running under ancient Jerusalem was indeed constructed around 700 B.C., during the reign of King Hezekiah, just as it is described in the Bible.

The tunnel, which is about 500 meters (550 yards) long, brings water from the Gihon Springs, located some 300 meters (330 yards) outside the walls of old Jerusalem, to the Siloan Pool inside the ancient city. It was built to protect the city's water supply during an Assyrian siege.

Structures described in the Bible are notoriously difficult to date. While some are poorly preserved or hard to identify, others are off limits to scientists because of political reasons. The age of the Jerusalem tunnel had been in dispute, with dissident scientists arguing it is not as old as the Bible suggests.

The new research should put those doubts to rest. The biblical text appears to present an accurate historical record of the tunnel's construction. It is one of the longest ancient water tunnels without intermediate shafts.

"The tunnel was a major technological achievement," said Amos Frumkin of the geography department at Hebrew University in Jerusalem, who led the research. "It's one of the most ancient structures that's still in use."


Scientifically linking the tunnel to the time of King Hezekiah, who ruled the Jewish kingdom from 727 B.C. to 697 B.C., was difficult because researchers had little archaeological evidence to work with.

An inscription written in ancient Hebrew, which was found at the lower entrance to the tunnel, describes how two groups of men dug the tunnel from different directions. Unlike other ancient inscriptions, however, this epitaph did not mention the king who commissioned the tunnel's construction.

Frumkin and his colleagues ignored the archaeological evidence altogether. Instead, they analyzed pieces of plants embedded in the floor of the tunnel. Since radiocarbon, which is found in all plants, disintegrates at a known rate, Frumkin was able to measure exactly when the plants died.

Using a similar radio-dating method to obtain a minimum age for the tunnel, the researchers also dated stalactites, which had formed inside it.

"We can constrain the age of the tunnel by analyzing things that grew before it was constructed and things that grew after it was built," said Frumkin. "We found that the tunnel is 2,700 years old, which corresponds with the Bible."

Saved by a Miracle

Scholars believe King Hezekiah commissioned the tunnel for security reasons to supply his subjects with water during an imminent siege by the Assyrians.

"The spring water comes out in the valley and not in the city," said Frumkin. "The ultimate solution was to bring the water into the city. The tunnel takes the water by gravitation down to a pool which is built inside the city."

The construction of the tunnel is described in detail in Kings and Chronicles in the Bible. Scholars have long debated its historical importance.

"In the Bible, the city [of Jerusalem] was saved by a miracle," said Hershel Shanks, editor of Biblical Archaeology Review. "However, the Bible does tell us that Hezekiah built this tunnel and apparently that is what enabled the Israelites to withstand the siege."

At one point, after the tunnel was built, the spring is believed to have been sealed to conceal it from the enemy. Most people only knew the Siloan Pool and lower end of the tunnel. It wasn't until the late Middle Ages when people walked into the tunnel that they found it was connected to the spring.

"We have known about the tunnel for a long time," said Frumkin, who began researching the tunnel while he was in high school in the late 1960s. "It just hasn't been dated."

Hard to Date

Modern equivalents of structures described in the Bible are hard to locate and date. Most sites are not associated with enough geographical information to be identified, and many structures have been destroyed during warfare. Others, like the Temple Mount in Jerusalem, are easily identified but impossible to study because of political reasons.

"The main problem is that we don't have a lot of material that can be dated," said Frumkin. "Unlike in archaeological dating, which relies on comparison of artifacts, it's very rare to have material available for radiometric dating."

There are still many structures described in the Bible, like some of the gates leading into ancient Jerusalem, that have not been dated.

"It's quite rare to be able to go into structures that were constructed thousands of years ago to try to understand the people who lived during this time," said Frumkin. "But if we can date the structure, we will be able to know if what is written in the Bible is real."

A summary of the research is described in today's issue of the science journal Nature.

© 1996-2008 National Geographic Society. All rights reserved.