The Western Wall is important to modern Jews because it is the only remaining relic of the Second Temple, which was a sacred center of the Jewish religion in ancient times. The building was destroyed by the Romans in 70 A.D.
In Hebrew, the Wall is referred to as the "Kotel." In ancient times, Biblical Law required pilgrimages to the Temple, a tradition which is still echoed in the festivals and pilgrimages that Jews still make there. When the building was destroyed by the Romans, its remaining outer wall became symbolic of the challenges the Jews faced through the changing times. The Wall was under Islamic rule for over a thousand years, during which time Jewish individuals were not allowed to approach it. The ban was finally lifted at the end of the Six Day War in 1967.
Now, many Jewish men journey to the Wall to pray and to insert prayer requests, including former Israeli Defense Minister Moshe Dayan, who was among the first to reach the wall after the long ban. His request was a seemly simple one - enduring peace for the Israelis. The tradition of inserting prayers into the Wall is so common that professional services offer to insert prayers on behalf of those who are not able to make the pilgrimage.