The Kidron Valley in Jerusalem has several ancient tombs in it. The Bible records that Absalom, son of King David, built a monument for himself in the King’s Valley.
Now Absalom in his lifetime had taken and set up for himself the pillar that is in the King’s Valley, for he said, “I have no son to keep my name in remembrance.” He called the pillar after his own name, and it is called Absalom’s monument to this day. (2 Samuel 18:18 ESV)
In AD 1170 Benjamin of Tudela associated one of the monuments in the Kidron Valley with the monument of Absalom. The monument actually belongs to the early first century B.C. It is a funerary monument in front of an eight-chambered tomb.
Joe Zias, of Hebrew University, was able to locate an inscription on the right side of the monument in 2002. The inscription is written in Byzantine Greek of the fourth century AD and reads,
This is the tomb of Zacharias, martyr, very pious priest, father of John.
Could this be the priest Zacharias (also spelled Zechariah in English versions) who was the father of John the Baptist? I think the best we can do is agree with Murphy-O’Connor,
Such Byzantine identifications reflect the piety of the period and have no historical value.