Al Aqsa Mosque
Muslims also hold the Temple Mount to be sacred because of the legend of the Night Journey of Mohammed, wherein the Muslim prophet ascended to heaven from the "the farthest mosque," associated with the Temple Mount, while in the midst of a dream.
When Muslims conquered Jerusalem from the Byzantines in 638 A.D., they immediately gravitated toward the most ancient center of holiness in Jerusalem: The Temple Mount. On this mountain they built Al Aqsa ("the farthest") Mosque, which today is considered by many Muslims to be the third-holiest site in Islam. Muslim devotion to this site can be traced to the legend of Mohammed's Night Journey.
So Umar built Al Aqsa Mosque, which began as a large but plain building that could accommodate up to 3,000 worshipers. Later the Dome of the Rock and other structures were built on the Mount, to form the Haram Al-Sharif compound (Arabic for "Noble Sanctuary").
Over centuries, the original plain building evolved into a much more ornate structure, with colonnades, minarets and a lead-covered dome. A richly designed ablution fountain lies outside the mosque, because worshipers are required to wash themselves before entering the mosque for prayers.
Al Aqsa Mosque was rebuilt several times after being destroyed in various earthquakes and a particularly disastrous fire. Today, King Abdullah II of Jordan is building a minaret in honor of his father, King Hussein, which will be the tallest structure in the Old City.
The mosque compound is open to non-Muslim visitors except on Fridays and holidays, though not all interior parts are open to the public. Modest attire is required, and you may be asked to remove your shoes as a sign of humility on holy ground.