The Room of the Last Supper lies in the second floor of a building on Mount Zion, in Jerusalem, just outside the Dormition Church behind the Franciscan house on Sion, and south of the Zion Gate in the Old City walls.

On the basement of the building is King David's Tomb .

The building was the seat of the Mother Church of Jerusalem for many years, and is a remnants of the Franciscan medieval Friary.

The Last Supper Room is devided by three pillars 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 13th century, on top of a much older structure. The older structure, according to the archaeological research, was a church-synagogue of the early Christian community of Jerusalem.

After the Franciscan Friars' eviction, this room was transformed into a mosque, as evidenced by the mihrab in the direction of Mecca and an Arabic inscription prohibiting public prayer at the site.