Siena Cathedral interior is a feast for the eye, with black and white marble combined with arches along the sides of the nave,
side chapels and gigantic composite columns.

The floors are solidly covered with precious marble inlays designed in the 13th-14th centuries.
Designed by many different artists, the inlaid marbles show Sibyls, (female prepohetesses from antiquity))
and stories from the Old Testament.

The floors are usually covered for preservation, but generally one or two sections are left uncovered , (but roped off), for visitors to admire.
(see next image).