The same element, a curved screen with a volute on each end, is repeated in six pieces to form a single three-lobed figure. Each element engages with another, on both sides, so as to close the circle and obtain an interior space accessible through passages between the volutes.
Therefore, to enter, one must accompany the spiral movement of the diaphragms, first in one direction, then in the other; this particular movement, combined with the internal symmetry, ensures that once inside, it’s difficult to recognize the passageway through which one entered; the curved walls dissemble their dimensions, so that one must walk through them all to be able to assess them.