The Temple Mount in Jerusalem is holy to the Muslims and the Jews. It is believed to be the spot where Abraham offered to sacrifice his son Isaac. The Muslims believe the same story except that they believe that Abraham was offering his son Ishmael. After the Romans defeated the Jews in the first Jewish revolt the Temple was not rebuilt. This sacred area remained an open area until the Muslims conquered the land and then built the Dome of the Rock on this spot. This means that the Temple Mount had no structure on it for over 600 years. The Dome of the Rock is the earliest Muslim monument still in existence. It still has the original decorations and marble columns since it was built in 696 CE.  The purpose of the Dome of the Rock is to enshrine a sacred focal point in its center and it is not a mosque or a place of worship. The Muslims did build the al-Aqsa which is a mosque just south of the Dome of the Rock and this is where pilgrims go to worship.

(The Great Courses – The Holy Land)