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Al-Aqsa, because it was built by a Prophet and Allah had taken Prophet Muhammad in a night to that mosque ( according to Quran) and he performed prayer
Jerusalem is a Holy city in Judaism, Christianity & Islam.
Jerusalem.
== Mecca.
Is The Dome of the Rock a religious holy site for Christians,Muslims ,or Jews
The site of the Holy Temple in Jerusalem. We worship at the Western Wall which is adjacent to it.
Christian knights hoped to recapture Jerusalem from the Muslims during the Crusades. The city of Jerusalem held great religious significance to Christians as the site of Jesus Christ's crucifixion and resurrection.
It is the East of Jerusalem (or AlQods) where there are the Western Wall and the Temple Mount Complex (that are holy places for Jews) and Al-Aqsa mosque (that is considered the third of the three holiest mosques in Islam history). For both Muslims and Jews the whole site of Al-Qods (Jerusalem) is holy.
Actually all three claim it as their holy city the Jews, christians and also Muslims do claim it as theirs.
Bethlehem, Calvary and Jerusalem are holy to Christians. The temple mount which is the base where the temple of Solomon used to stand is holy to Jewish people and for some reason the same spot is called holy by muslims because muslims built a mosque where the temple of Solomon used to be.
The Muslims have the Dome of the Rock Shrine and the Al-Aqsa Mosque which form a single holy site together.
The holy site of Islam is located in Mecca, Saudi Arabia. Specifically, the Kaaba is located there (it's a giant black cube). The Kaaba is the most sacred and holy site in Islam. When Muslims pray, wherever they are on the globe, they pray in a certain direction so that way they are facing the Kaaba. They once faced Al-Aqsa (another holy site in Islam) Jerusalem as the direction of prayer.
Jerusalem is where Islam's third most holy site, The Mosque of Al-Aqsa, is located. For Jews, Jerusalem is important because it is the site of their holiest place, the temple mount. For Christians it is important because Jesus was crucified, buried and rose from the dead in Jerusalem. Muslims, Jews and Christians all come to Jerusalem on pilgrimages to see it.