Siena Cathedral Audio Guide

The Vast Nave

Stepping inside, the sheer scale of the cathedral becomes apparent. The central nave stretches exactly 89.4 meters from the entrance to the high altar, creating a powerful sense of depth. This space is defined by a repetitive rhythm of massive pillars and arches, all clad in the city’s signature black and white stripes. Looking upward, the vaulted ceilings are decorated in a deep sky motif, featuring hundreds of gilded stars set against a rich blue background. This design was intended to transform the interior into a representation of the cosmos. The floor beneath you is equally complex, covered in a vast series of marble mosaics that tell stories from the Bible and classical mythology. The visual pull created by the parallel rows of columns naturally leads your gaze toward the crossing, where the dome rises above the altar. This interior space took over a century to complete, and you can see how different architectural styles, from Romanesque to Gothic, blend together. The interplay of the striped masonry and the starry vaults creates a uniquely immersive environment that feels grounded in local identity.

The Frieze of Popes

Just below the vaulted ceiling, a continuous cornice runs the entire length of the nave and the choir. Set into this ledge are 171 busts made of plaster, each representing a different Pope. The series begins with Saint Peter at the far end and follows the chronological order of the papacy up to the early 15th century. Each figure is labeled with the Pope's name on a small plaque below. This massive undertaking was more than just a history lesson; it was a strong political statement. During the Middle Ages, Siena was a powerful and often defiant city-state. By placing the entire lineage of the Church in such a prominent position, the city's leaders were publicly declaring their spiritual and political alignment with the authority of Rome. The busts were created in a relatively short period by a group of local sculptors, which explains the stylistic consistency among them. They are positioned so that they look slightly downward, as if observing the ceremonies taking place in the nave below. This creates a sense of continuous historical presence, connecting current visitors with the long tradition of the institution.

Busts of the Emperors

If you look at the triangular spaces, or spandrels, located between the main arches of the nave, you will see a second set of portraits. These 36 busts depict various Holy Roman Emperors from different eras. Their placement directly beneath the Popes is highly symbolic of the medieval world’s political structure. In the 13th and 14th centuries, Italian politics were often dominated by the struggle between the supporters of the Pope and the supporters of the Emperor. By including both groups in the cathedral’s decoration, Siena was illustrating the idea that the world was governed by two powers, the spiritual and the secular, which were meant to support each other. These imperial busts are smaller than the papal ones above them, suggesting a hierarchy where secular power is subordinate to divine authority. The figures are carved with individual traits, though many are stylized representations rather than true likenesses. This double frieze turns the upper reaches of the nave into a visual record of the dual authorities that shaped the lives of everyone in medieval Europe.

Allegory of the Hill of Wisdom

Pinturicchio · 1505

This elaborate marble panel is one of the most intellectually complex sections of the cathedral floor. Designed by the Renaissance master Pinturicchio in 1505, it presents an allegory of the human struggle to achieve wisdom. The lower part of the scene shows a group of figures landing on a rocky shore after navigating a turbulent sea representing Fortune. One figure, representing Fortune herself, stands precariously with one foot on a sphere and the other on a boat, holding a wind-filled sail to show her unpredictable nature. Above her, a steep and treacherous path leads up the Hill of Wisdom. At the very summit, you can see the ancient Greek philosophers Socrates and Crates. Socrates receives a palm branch, symbolizing victory over earthly desires, while Crates empties a basket of jewels into the sea, showing his rejection of worldly wealth in favor of intellectual pursuit. The mosaic teaches that the path to virtue is difficult and requires turning away from material goods. The fine lines and shaded effects were achieved by etching into the marble and filling the grooves with black pitch.

The Pulpit Lions

At the very base of the pulpit, several columns rest directly on the backs of sculpted lions. This was a common motif in Italian medieval architecture, but these particular lions are carved with exceptional intensity. If you look closely at the figures beneath their paws, you’ll see that some of the lions are in the act of hunting or devouring other animals, like horses or goats. This imagery carries a specific symbolic meaning from the Middle Ages. The lion was seen as a protector of the sacred space, representing the power and vigilance of the Church. The act of devouring prey symbolized the Church's triumph over sin and its ability to defeat those who opposed its teachings. Conversely, the lions were also seen as protective figures, nursing their cubs to represent how the Church provides spiritual nourishment to the faithful. These figures ground the elevated, heavenly scenes depicted on the panels above in a more visceral, earthly reality. The wear on the stone, particularly on the heads and paws of the lions, shows where centuries of visitors have touched them.

Piccolomini Library

Tucked away off the north aisle of the cathedral is the Piccolomini Library, one of the most vibrant rooms of the Italian Renaissance. It was commissioned in 1492 by Cardinal Francesco Piccolomini, who later became Pope Pius III. He intended the space to be a monument to his uncle, Enea Silvio Piccolomini, better known as Pope Pius II, and a home for the uncle’s extensive collection of manuscripts. The room is famous for its ten large frescoes painted by Pinturicchio and his workshop between 1502 and 1507. These murals depict key scenes from the life of Pius II, from his early days as a diplomat to his election as Pope. Remarkably, these frescoes have never undergone a major restoration; the colors you see are the original pigments, preserved by the room’s stable environment. The ceiling is equally impressive, covered in intricate patterns and gold leaf that glitters under the lights. In the center of the room, rows of large, illustrated choir books are displayed under glass, showing the kind of scholarly treasures the library was built to protect.

The Three Graces

Standing in the center of the library, this ancient Roman sculpture of the Three Graces is a copy of a lost Greek original. It might seem unexpected to find three nude figures from pagan mythology in a room commissioned by a Cardinal, but their presence perfectly illustrates the intellectual climate of the Renaissance. To the scholars and churchmen of the time, the study of classical antiquity was not at odds with their faith. Instead, they believed that the perfection and balance found in Greco-Roman art reflected the underlying harmony of God's creation. This group was likely acquired in Rome and brought here to serve as a model for artists, symbolizing the 'rebirth' of classical ideals. The figures represent charm, grace, and beauty—qualities that the Piccolomini family wanted associated with their heritage. While most medieval art focused on religious narratives, this piece represents a shift toward a humanistic appreciation for form and aesthetic pleasure. Notice how the three figures are intertwined, creating a circular rhythm that draws the eye around the sculpture. This fluidity of movement became a hallmark of the new artistic era that was beginning to blossom across Italy.

The Chigi Chapel

Known as the Chapel of the Madonna del Voto, this space is a dramatic departure from the Gothic surroundings of the cathedral. It was designed in the mid-17th century by the Baroque master Gian Lorenzo Bernini for Pope Alexander VII, a member of the powerful Sienese Chigi family. At the heart of the chapel sits the Madonna del Voto, a 13th-century icon of the Virgin and Child. This image holds profound significance for the people of Siena. In 1260, on the eve of the pivotal Battle of Montaperti against Florence, the city’s leaders formally dedicated Siena to the Virgin Mary, laying the keys of the city at her feet and begging for her protection. After their surprising victory against a much larger Florentine force, the Sienese solidified their identity as 'the City of the Virgin.' This chapel serves as a lavish sanctuary for that devotion. Bernini transformed the space with rich architectural details, creating a theatrical environment where light and shadow play across the surfaces. It remains a place of deep prayer and historical remembrance, linking the city’s medieval military triumphs with the artistic splendor of the high Baroque period.

Altar of the Siena Cathedral

The high altar serves as the spiritual and architectural focal point of the entire cathedral. This massive structure was designed in the 1530s by the Sienese architect Baldassarre Peruzzi. Its classical lines and grand scale were intended to provide a fitting stage for the cathedral's most important religious ceremonies. Before this altar was built, the space was occupied by Duccio di Buoninsegna’s famous 'Maestà,' one of the most significant altarpieces in Western art. That painting was eventually moved and is now housed in the nearby Cathedral Museum to ensure its preservation. Peruzzi’s design represents a transition toward a more monumental, Renaissance-inspired aesthetic. The altar is not just a table for the liturgy; it is a complex architectural monument. It anchors the deep choir and provides a base for the elaborate bronze tabernacle that rises above it. By placing such a large and formal structure here, the church leaders aimed to emphasize the importance of the Eucharist and the central mystery of the mass. Every line of the nave and every arch of the dome ultimately leads your eye toward this point, reinforcing its role as the heart of Sienese religious life.

The Starry Dome

Looking straight up from the crossing of the cathedral, you are met with the sight of the magnificent octagonal dome. This structure is famously decorated with a pattern of gold stars set against a vibrant blue field, creating the impression of a permanent night sky inside the church. The dome reaches a height of 48 meters, and its geometry is emphasized by the white and black striped pillars that support it. Notice the ring of sculpted figures around the base of the dome—these represent 42 patriarchs and prophets from the Old Testament, gazing down into the nave. The light that floods into this central space comes from the lantern at the very top. This lantern was a later addition, designed by the Baroque master Gian Lorenzo Bernini in the 17th century. He was brought in to improve the lighting and add a final touch of grandeur to the structure. The transition from the dark, rhythmic stripes of the pillars to the bright, celestial blue of the dome represents a journey from the earthly to the heavenly. It is one of the most iconic views in Italy, capturing the ambition of the medieval builders who wanted to touch the sky.