Where is Mount Zion located?
In history, there are 3 places that have been known as “Mount Zion”, all located in the present-day city of Jerusalem.
1) David captured the fortress of Zion — which is the City of David. (2 Samuel 5:7)
The original “Mount Zion” was the Jebusite fortress on the southern part of Jerusalem's Eastern Hill. King David conquered it in about 1000 BCE and is believed to have built his palace there. This area became known as the City of David.
2) Then Solomon began to build the temple of the Lord in Jerusalem on Mount Moriah, where the Lord had appeared to his father David. (2 Chronicles 3:1)
Solomon built his Temple on Mount Moriah, north of David’s palace. After the temple was completed, this area became known as "Mount Zion". Today, this is known as the Temple Mount.
3) By the first century CE, “Mount Zion” was used to refer to ancient Jerusalem’s Western Hill, which is higher than the Eastern Hill. The then long-lost palace of King David was believed to have been there. Events of the early Christian church believed to have taken place there include the Last Supper and the Council of Jerusalem (Acts 15).