The room of the Last Supper is located near Mount Zion which lies to the south of today's city walls. Coming out of Zion Gate you are faced with the Benedictine Basilica of the Dormition. The room of the Last Supper lies just beyond the Dormition Abbey behind the Franciscan house on Sion. The whole area has been changed by religious Jews into various Yeshivas (Schools of the Torah) especially due to the value of the Tomb of King David which is believed to be located beneath the Upper Room.

This was the seat of the Mother Church of Jerusalem for many years. Additionally, this was also the first Friary the Franciscans bought through the Kings of Naples and from which they have been banished. The structures around the "Upper Room" are in fact remnants of the Franciscan medieval Friary. Upon entering the "Upper Room" you find yourself in a large hallway. The ceiling is supported by three pillars which separate the room into three naves. The pillars and the arches, windows and other Gothic style architectural elements are a clear indication the room was built by the Crusaders in the early 14^th century, on top of a much older structure most probably pre-dating even the first churches constructed in Palestine. According to the archaeological research, this was a church-synagogue of the early Christian community of Jerusalem.

The "Upper Room" brings to mind the scene of momentous events recounted in the Gospels: the institution of the Eucharist during the Last Supper, Jesus' appearance before the Apostles after His Resurrection and the descent of the Holy Spirit over the Apostles at Pentecost. The final episode is commemorated in the Chapel of the Descent of the Holy Spirit, exactly above the room where King David's Tomb is honored.

After the Franciscan Friars' eviction, this room was transformed into a mosque, as revealed by the mihrab (the niche indicating the direction of Mecca for prayers). The Arabic inscription prohibiting public prayer at the site, can still be seen on the wall.

Luke 22:8-38 recounts the story of the Upper Room. "And He sent Peter and John, saying, 'Go and prepare the Passover for us, that we may eat.' So they said to Him, 'Where do You want us to prepare?' And He said to them, 'Behold, when you have entered the city, a man will meet you carrying a pitcher of water; follow him into the house which he enters. Then you shall say to the master of the house, 'The Teacher says to you, 'Where is the guest room where I may eat the Passover with My disciples?' Then he will show you a large, furnished upper room; there make ready. So they went and found it just as He had said to them, and they prepared the Passover. When the hour had come, He sat down, and the twelve apostles with Him. Then He said to them, 'With fervent desire I have desired to eat this Passover with you before I suffer; for I say to you, I will no longer eat of it until it is fulfilled in the kingdom of God.' Then He took the cup, and gave thanks, and said, 'Take this and divide it among yourselves; for I say to you, I will not drink of the fruit of the vine until the kingdom of God comes.' And He took bread, gave thanks and broke it, and gave it to them, saying, 'This is My body which is given for you; do this in remembrance of Me.' Likewise He also took the cup after supper, saying, 'This cup is the new covenant in My blood, which is shed for you. But behold, the hand of My betrayer is with Me on the table. And truly the Son of Man goes as it has been determined, but woe to that man by whom He is betrayed!' Then they began to question among themselves, which of them it was who would do this thing. Now there was also a dispute among them, as to which of them should be considered the greatest. And He said to them, 'The kings of the Gentiles exercise lordship over them, and those who exercise authority over them are called benefactors. But not so among you; on the contrary, he who is greatest among you, let him be as the younger, and he who governs as he who serves. For who is greater, he who sits at the table, or he who serves? Is it not he who sits at the table? Yet I am among you as the One who serves. But you are those who have continued with Me in My trials. And I bestow upon you a kingdom, just as My Father bestowed one upon Me, that you may eat and drink at My table in My kingdom, and sit on thrones judging the twelve tribes of Israel.' And the Lord said, 'Simon, Simon! Indeed, Satan has asked for you, that he may sift you as wheat. But I have prayed for you, that your faith should not fail; and when you have returned to Me, strengthen your brethren.' But he said to Him, "Lord, I am ready to go with You, both to prison and to death.' Then He said, 'I tell you, Peter, the rooster shall not crow this day before you will deny three times that you know Me.' And He said to them, 'When I sent you without money bag, knapsack, and sandals, did you lack anything?' So they said, 'Nothing.' Then He said to them, 'But now, he who has a money bag, let him take it, and likewise a knapsack; and he who has no sword, let him sell his garment and buy one. For I say to you that this which is written must still be accomplished in Me: And He was numbered with the transgressors. For the things concerning Me have an end.' So they said, 'Lord, look, here are two swords.' And He said to them, 'It is enough."