Cripta del Duomo di Siena

Under the choir of Siena Cathedral, excavations begun in 1999 broke into a room that had been filled with rubble since the fourteenth century. On its walls ran a late thirteenth-century fresco cycle whose colours — sealed away before they could fade — survived almost as they were painted.

Why it matters

The Crypt is the rarest kind of art-historical find: not a work recovered and restored, but a room that simply stopped existing. When the Opera della Metropolitana commissioned excavations in 1999 to recover spaces around the oratory of Saints Giovannino e Gennaro beneath the choir, the work uncovered a decorated hall the official site calls one of the most important archaeological discoveries of recent decades. Its fresco cycle, painted in the second half of the Duecento by artists working in the circle of Guido da Siena, Dietisalvi di Speme, Guido di Graziano and Rinaldo da Siena, had been buried when the room was filled with inert material — probably in the second half of the Trecento — and that burial, the encyclopedia notes, preserved the painting almost unique in the history of art. For visitors, the Crypt doubles the story of the Cathedral above: the same building campaign seen from below, at the level where the twelfth-century church actually began.

What to notice

Stand at the foot of the stairs and let the colour register first: unlike almost every fresco cycle of its date, these paintings were never exposed to daylight for centuries, so blues, reds and ochres stay close to their original pitch. The walls carry biblical narrative in two registers — Old Testament scenes above, New Testament below — with the Passion underlined in three scenes of special weight: the Crucifixion, the Deposition from the Cross and the Entombment. Colour is not confined to the figures: columns, pilasters, capitals and corbets are painted with geometric and vegetal motifs, so the room reads as a total surface rather than a picture gallery. Look also at the architecture the excavations exposed: the stone walls of the twelfth-century choir and left transept, visible through the fourteenth-century brick transformations, and the foundations of the Cathedral's oldest apse, which the dig clarified. The official plan names scenes such as the Annunciation, the Nativity and the Rest on the Flight into Egypt among the identifiable subjects.

Context and history

The space belonged to the earliest cathedral complex: its stone walls belong to the twelfth-century choir and transept. When the Opera decided in the fourteenth century to expand the Cathedral toward Piazza San Giovanni — the campaign that produced the Baptistery below the new choir — the room was transformed, absorbed into new brick structures with pointed windows, and finally filled with rubble, probably in the second half of the Trecento, as static problems caught up with the great expansion project known as the Duomo Nuovo. There the paintings slept for six hundred years until the 1999 excavations, with further discoveries following in 2003. The name Crypt, both sources caution, is evocative rather than strict: the Cathedral's true liturgical crypt is believed to lie under the dome, in areas still inaccessible for structural reasons. Opened to the public as a museum site of the Opera della Metropolitana, the room is now part of the same circuit as the Cathedral, the Baptistery and the Museo dell'Opera.