About Saint Martha’s House (Domus Sanctae Marthae, Casa Santa Marta) in Rome:
Saint Martha’s House is a building adjacent to St. Peter’s Basilica in Vatican City. Completed in 1996, during the pontificate of Pope John Paul II, it is named after Martha of Bethany, who was a sibling to Mary and Lazarus of Bethany. The building functions as a guest house for clergy having business with the Holy See.
It also serves as the temporary residence of members of the College of Cardinals while participating in a papal conclave to elect a new pope. Prior to the construction of Domus Sanctae Marthae, cardinals participating in conclaves lived in the Apostolic Palace, sleeping on cots in makeshift spaces throughout the palace, some within hallways and offices, often divided from one another by a sheet hanging on a rope. They shared common bathrooms, often with ten cardinals assigned to each.
Pope Francis had lived in a suite in the building since his election in March 2013, declining to use the papal apartments in the Apostolic Palace.
The building is not open to the general public unless it is someone having business at the Vatican, and as stated before, that is almost always members of the clergy.