The room upstairs, and the New Testament calls it three different things. Luke 22:11 has Jesus ask for the katalyma, the GUEST ROOM — the same word Luke uses of the crowded house in Bethlehem at 2:7. The next verse calls it an anagaion, an upper room, a word that occurs twice in the New Testament and both times in this scene (Luke 22:12; Mark 14:15). And Acts 1:13 calls it a hyperōon, the upstairs room where the eleven wait between the ascension and Pentecost. ⚠ Luke ties the two events to one place: the Last Supper happens in an upper room, and the disciples afterwards go back to the room where they were staying. ⚠ A building on Jerusalem's Western Hill has been identified with that room since at least the fourth century. Jacob Pinkerfeld excavated it after 1948 mortar damage, dug down through Arab, Crusader and Byzantine floors to a Roman-period floor, and dated the massive lower courses and that floor to the FIRST CENTURY. He read the building as a synagogue and was killed in 1956, before the graffiti found on its collapsed first-century plaster had been translated. The translation, when it came, included ‘O Jesus, that I may live’ — which reframed the building as a JUDEO-CHRISTIAN synagogue, a meeting-house built by Jews who followed Jesus, and matched Eusebius's report (c. 318) of a large church on the Western Hill built by Jews. ⚠ And its Torah niche does not face the Temple Mount. It faces north-west, toward Golgotha and the empty tomb. Whatever else that is, it is a deliberate architectural decision about where the centre had moved. See the video below, and the entry for GOLGOTHA for the site it points at.