Wikipedia on the Temple Mount:
Judaism regards the Temple Mount as the place where God chose the Divine Presence to rest (Isa 8:18); according to the rabbinic sages whose debates produced the Talmud, it was from here the world expanded into its present form and where God gathered the dust used to create the first man, Adam…From that location the word of God will come out to all nations, and that is the site where all prayers are focused. According to Jewish tradition and scripture (2 Chronicles 3:1-2), the first temple was built by Solomon the son of David in 957 BCE and destroyed by the Babylonians in 586 BCE. The second was constructed under the auspices of Zerubbabel in 516 BCE and destroyed by the Roman Empire in 70 CE. Jewish tradition maintains it is here the Third and final Temple will also be built. The location is the holiest site in Judaism and is the place Jews turn towards during prayer. Due to its extreme sanctity, many Jews will not walk on the Mount itself, to avoid unintentionally entering the area where the Holy of Holies stood, since according to Rabbinical law, some aspect of the Divine Presence is still present at the site. It was from the Holy of Holies that the High Priest communicated directly with God.