The historic Yad Avshalom monument in Jerusalem's Kidron Valley, revered for centuries as a Jewish shrine, was also a Christian holy place in the fourth century, new evidence has revealed.

A fourth-century inscription on one of the walls near the monument, recently uncovered by chance, marks the site as the burial place of the Temple priest Zachariah, the father of John the Baptist who baptized Jesus.

Scholars believe the monument was built in the first century, making it possible that figures holy to Christians could be buried there. According to Jewish belief, Yad Avshalom was named for Absalom, the son of King David, since Samuel II relates that Absalom built a memorial in "the valley of the king" which lies below the Temple Mount. Absalom died more than 1,000 years earlier.

Parts of the inscription were discovered two years ago but the deciphering was only recently completed. Results of the research were published in the Revue Biblique in Paris two weeks ago.

A Jerusalem archaeologist, Joe Zias of the Antiquities Authority, uncovered the inscription. He noticed in an ancient picture of the tomb that there was writing on one of the walls surrounding it. The ancient Greek letters had meanwhile been almost completely obliterated and therefore not seen by the dozens of archaeologists and scholars who had studied the monument in more modern times.

Zias visited the site and spoke to the photographer - and only then did he understand the mystery. "The inscription can be seen only when the sun hits it from a certain angle at twilight, and only in summer," Zias said. He tried to create a copy of the inscription but faced difficulties since it is located nine meters above ground.

Zias collected funds to build scaffolding and made a silicon copy. At this point, Zias approached his colleague Father Emile Puech of the East Jerusalem Ecole Biblique, the Dominican order's archaeological and biblical research institute. Puech is a renowned philologist who helped in deciphering the Dead Sea scrolls.

Puech found 47 letters in the inscription, which is 1.2 meters long and 10 cms high. It reads: "This is the tomb of Zachariah, the martyr, the holy priest, the father of John." The Gospel of Luke names Zachariah and Elisabeth as the parents of John the Baptist.

Another mausoleum, known as Kever Zachariah - the tomb of Zachariah the prophet - is situated close to Yad Avshalom, which creates confusion.

According to Puech, the inscription dates from the Byzantine empire of the 4th century, meaning the inscription was written 300 years after the tomb was built. It at least proves the tomb was a Christian holy site then, even if it does not categorically prove for whom it was built.

According to Hebrew University expert Prof. Gideon Foerster, the inscription tallies with a sixth century Christian text that says Zachariah, the father of John the Baptist, was buried with Simon the Elder and James, the brother of Jesus. Foerster believes the document and inscription are historically authentic.

Zias and Fuech are deciphering additional inscriptions found on the walls and will publish their findings in November. They say that one of the words in the inscriptions is Simon.

Zias says he has no illusions: "Even if we prove there is no connection between Absalom and Yad Avshalom this will be forgotten in another 50 or 100 years."