The Western Wall is the most sacred site accessible to Jews as it is the only remaining part of the Temple Mount, held to be uniquely holy in Judaism.
The site of the former temple on Temple Mount now houses the Dome of the Rock mosque, the cause of violent disputes.
But for religious reasons Jews are forbidden to go there in case they tread on the site of the Holy of Holies, thought to be located under the Dome of the Rock.
King Herod built the Western Wall in 20 BC during an expansion of the Second Temple. When the Romans destroyed the temple in 70 AD the retaining wall survived.
For hundreds of years, Jews came to pray in the small area of the wall that could be seen, posting folded pieces of paper containing prayers in cracks in the ancient stones.
It became known by Europeans as the Wailing Wall, a translation of the Arabic el-Mabka, which means place of weeping.