The Temple Mount, as it is known to Jews and Christians, or the Noble Sanctuary as it is known to Muslims, is a place in the Old City section of Jerusalem, Israel. It is significant in Christianity, Islam, and Judaism. Currently, the Temple Mount is home to the Western Wall and the Dome of the Rock.
The Western Wall is just that—a wall. It's actually the wall of the Second Temple. After the Second Temple was destroyed, Jews visited the only remaining wall, turning it in to a place of prayer. The wall is sometimes called the Wailing Wall, referring to the mourning, praying Jews.
The Western Wall is near the Kadosh Hakadashim, or the Holy of Holies—the most sacred place in the Jewish faith. The Kadosh Hakadashim refers to the inner sanctuary of the Temple.
Not only is it a sacred place for Jews, but for Muslims as well. Muslims regard the site as the third holiest in Islam. Mecca is generally considered the most sacred, and Medina, the second holiest. For Muslims, the Temple Mount is important because it's the place that Muhammad was taken to to accompany the Archangel Gabriel on a tour of heaven.
While Christians find references to the Temple Mount in their bible, Christians generally do not regard it as sacred a site as Jews or Muslims do. For Christians, the Temple Mount is referenced as the place where Jesus prayed and the place he protected as sacred against secular business and financial practices.
Control over the Temple Mount has changed hands many times throughout history. At one point it was the site of the First Temple, then after its destruction, the Second Temple. After the Second Temple was destroyed, a Third Temple was not built. There is much speculation over why — Jews believe that a Third Temple will be built when the Messiah comes and that it will be the final temple.
Some time after the destruction of the Second Temple, Muslims gained control over the region, and the Dome of the Rock and Al-Aqsa Mosque were built on the Temple Mount. While those structures were damaged or destroyed over time, newer versions exist there today. Still, both Israel and the Palestinian Authority lay claim over the area known as the Temple Mount. The Muslim Council currently controls the site.