A verse of the Quran refers to the "farthest Mosque":
Glory to (Allah) Who did take His servant for a Journey by night from the Sacred Mosque to the farthest Mosque, whose precincts We did bless,- in order that We might show him some of Our Signs: for He is the One Who heareth and seeth (all things). Quran 17:1
Some Muslims believe that refers to Al-Aqsa Mosque.
However, wikiIslam claims that this mosque did not exist at the time. (e.g. 610-613 AD.):
Muslims claim that Al-Aqsa mosque is mentioned in the Qur'an as the furthest mosque. Even though there was obviously no mosque in Jerusalem during Muhammad's time.
Did the Al-Aqsa mosque (or any mosque) exist at the time this passage was written?