Mount Zion is a hill located outside of the south walls of Old Jerusalem, by the Armenian Quarter, and a regular Israel tour stop for visitors. The Mount was mentioned in the Hebrew Bible for the City of David which he conquered (2 Samuel 5:7, 1 Chronicles 11:5; 1 Kings 8:1, 2 Chronicles 5:2), and also for the Temple Mount.
Some of the important Christian events which took place on Mount Zion include The Last Supper of Jesus with his disciples (Matthew 26:17-30; Mark 14:12-25; Luke 22:7-23; John 13:1—17:26), the coming of the Holy Spirit on the disciples in the form of a fire tongue on top of each disciples head (Acts 2:1-13), both events believed to have taken place on the holy site of the Cenacle. The appearance of Jesus before the high priest Caiaphas (Matthew 26:57-75), whom conspired to have Jesus killed, is believed to have taken place at the site of where the Church of St Peter stands today in Gallicantu. The Church of the Dormition, commemorates the "falling asleep" of the Virgin Mary on Mount Zion, as the Church name suggest. Around AD 50, the early Church debated converting gentiles (Acts 15:1-29), perhaps also in the holy site of the Cenacle.
At the times of the Old Testament, Zion was a city fortress which King David captured from the Jebusites naming it the City of David (2 Samuel 5:6-9). Later, perhaps when Solomon built the Temple Mount, it came to be named Mount Zion. After the 1st century AD, during the Roman destruction of Jerusalem, Mount Zion name was transferred to the present location outside the Old City walls.
In the time of Jesus, the hill was a wealthy neighborhood, populated and within the city fortress walls. The early church in the 1st century prayed on Mount Zion and built a church later known as the Church of the Apostles (Acts 1:1-13).
Over the centuries many churches were built on the holy site and destroyed. This also included the basilica Church of Hagia Sion (Holy Zion), a great Byzantine Church constructed by St. Helena and occupied the entire area where today stands the Church of the Dormition, the Tomb of David, and the Cenacle.
In the Old Testament King David is buried in the City of David (1 Kings: 2:10), the original city fortress of the Jebusites King David captured and renamed. Because Mount Zion original location was moved to this location after the destruction of the Temple by the Romans, Holy land pilgrims in the 10th century began commemorating the burial place of King David, and its actually the Christian Crusaders whom built the present memorial named the Tomb of King David on Mount Zion. Three of the walls of the tomb were apparently from the first century Judaeo Christian church.
After time, the memorial came to be accepted as David's tomb by all three major religions. An interesting side story is the respect in which Muslims held King David in the reconstruction of Old Jerusalem's walls by the conqueror Suliman in the 16th century. As the story goes, the sultan became en·raged when he learned that the new walls did not protect Mount Zion, leaving the Tomb of David outside the walls. Suliman summoned the two architects whom were the leaders of the construction project and ordered them to be beheaded. Today you'll find two graves near the Jaffa Gate that are said to be those of the architects.
Another place of interest to Christians traveling to the Holy Land and Jewish tourist alike on Mount Zion is the grave of Oskar Schindler, his life depicted in the Hollywood movie The Shindler's List, was a German industrialist whom saved more then 1200 Jews in the Holocaust, and has been declared a Righteous Gentile. You'll find his grave near the Zion Gates, in a catholic cemetery.