A staircase, solemn in style, leads from this room on the ground floor on the via Santo Spirito side to the first floor study. In the museum visit plan, the Atrium no longer functions as an entrance, but originally it and the monumental staircase allowed the two gents to access their suites, independently. Among the elegant fixed furnishings, the red marble basin of a Renaissance fragment set in 19th century elements catches the eye.