According to Jewish tradition the Divine presence used to appear through this gate and will appear again when the Messiah comes (Ezekiel 44:1-3) and a new gate will replace this one. It is also said that Jesus passed through this gate on Palm Sunday. The Ottoman Sultan sealed the gate in 1541. The Ottomans also built a cemetery in front of the gate believing that the precursor to the Messiah, Elijah, would not be able to pass through the Golden Gate and thus the Messiah would not come. This is based upon 1) according to Islamic teaching Elijah is a descendant of Aaron therefore making him a priest and 2) that a Jewish Rabbi is not permitted to enter a cemetery
Here is a link that provides cultural information about city gates. Remember that Revelations 21:25 tells us that in heaven "On no day will its gates ever be shut"