Two Jewish men tried to climb the Western Wall, Judaism's holiest site, because a water stain on one large stone has led some ultra-Orthodox Jews to conclude that redemption is near and the Messiah is on his way.

Rabbi Shmuel Rabinovitch, the chief rabbi of the Western Wall - also known as the Wailing Wall - said today the water stain was discovered four days ago by worshippers who pray at the base of the wall.

Some Jewish mystics believe it is a sign the "wall is crying," signalling the coming of the Messiah, he said.

Rabbi Rabinovitch and the Israel Antiquities Authority are closely watching to see if the 10-by-40 centimetre stain - found on a stone about halfway up the wall - grows or disappears.

AAP