Room of the Last Supper

The Upper Room is called the Cenacle which is a derivative of the Latin word cena, meaning dinner.  The Cenacle was the site of the Last Supper and most likely where the Apostles stayed in Jerusalem starting the Church.

Mark 14:12-17

On the first day of Unleavened Bread, when the Passover lamb was being sacrificed, His disciples said to Him, "Where do You want us to go and prepare for You to eat the Passover?"  And He sent two of His disciples and said to them, "Go into the city, and a man will meet you carrying a pitcher of water; follow him; and wherever he enters, say to the owner of the house, 'The Teacher says, "Where is My guest room in which I may eat the Passover with My disciples?" 

"And he himself will show you a large upper room furnished and ready; prepare for us there." 

The disciples went out and came to the city, and found it just as He had told them; and they prepared the Passover.  When it was evening He came with the twelve.

Acts 1:12-14

Then they returned to Jerusalem from the mount called Olivet, which is near Jerusalem, a Sabbath day's journey away.  When they had entered the city, they went up to the upper room where they were staying; that is, Peter and John and James and Andrew, Philip and Thomas, Bartholomew and Matthew, James the son of Alphaeus, and Simon the Zealot, and Judas the son of James.  These all with one mind were continually devoting themselves to prayer along with the women, and Mary the mother of Jesus, and with His brothers.