For "Zion" as a symbol for Jerusalem, redemption, etc. see Zion .Mount Zion is a hill in Jerusalem, located just outside the walls of the Old City. The term Mount Zion has been used in the Hebrew Bible first for the City of David and later for the Temple Mount, but its meaning has shifted and it is now used as the name of ancient Jerusalem’s Western Hill. In a wider sense, the term is also used for the entire Land of Israel.

More details: https://en.wikipedia.org/wiki/Mount_Zion