San Giovanni in Laterano is Rome's official cathedral and the mother of all churches in the Catholic world. Founded in the 4th century, it is the oldest and highest-ranking of the four major papal basilicas. The complex includes the basilica with its stunning Baroque interior, the beautiful 13th-century cloister, the ancient Baptistery, and the Holy Stairs (Scala Santa) that Christ allegedly climbed before his judgment. The papal throne stands here as the Bishop of Rome's seat.