Added to the UNESCO World Heritage Site list, the city center of Siena is distinctive for its winding streets and medieval and Renaissance buildings. Located in the Chianti Valley in Tuscany, a region renowned for its wine production, Siena is famous for its biannual horse race known as Palio, which attracts tourists worldwide. During the medieval and Renaissance period, Siena was also the hometown of influential artists like Simone Martini and Duccio di Buoninsegna, whose artworks can be admired in the city’s museums. Read on to discover more about Siena and its historic sites.
1. Piazza del Campo
The shell-shaped square paved with bricks is perhaps the most distinctive feature of Siena’s city center. Located at the intersection of three roads, Piazza del Campo was built on a stretch of marshy land drained in the 11th century and used to collect rainwater. A Campus Sancti Pauli (Field of Saint Paul) was first mentioned in the city record in 1169 when the city of Siena bought the area surrounding the present-day square. In 1193, the field was divided into two sectors by a wall, where, the following year, the offices of the Dogana delle gabelle (a customs post to collect gabelle, meaning taxes on trade) and the Zecca (Mint) were built.
Around the same time, the local government decided to unite the two sectors into an open space. Between 1262 and 1297, the Sienese authorities also introduced a series of ordinances to make the facades of the buildings facing the square more uniform. In particular, the measures dictated that the buildings had to incorporate twin-arched or triple-arched windows.
As the Government of the Nine (1287-1355) ordered the construction of the nearby Palazzo Pubblico, Piazza del Campo underwent a series of changes. Most notably, the sloping area was divided into nine sectors by ten rows of white travertine marble, a clear reference to the nine magistrates, known as noveschi, chosen among the members of the merchant and banking classes.
In the 15th century, Sienese artist Jacopo della Quercia built the Fonte Gaia, a marble fountain linked to the impressive network of tunnels dug to bring water to the city center. Today, the original marble statues adorning the fountain are replaced with 19th-century copies. Visitors can admire the original sculptures in the Santa Maria della Scala Museum.
Twice a year, on July 2 and August 12, the Piazza del Campo is covered by a layer of tuft and sand for the famous Palio, a horse race pitting the city’s 17 contrade (neighborhoods) against each other.
2. Palazzo Pubblico & Mangia Tower
Initially built between 1297 and 1310, the Palazzo Pubblico (Town Hall) was the seat of the Podestà and the Council of the Nine. The building, featuring a mixture of elements of Italian medieval and Gothic architecture, was also a symbol of Siena’s civic power. Construction of the new municipal building began on orders of the Nine Governors and Defenders of the Commune and People of Siena (commonly known as Council of the Nine), the republican regime that ruled Siena for sixty years, inaugurating a politically stable and prosperous time in a city previously plagued by internal divisions.
Its slightly concave facade presents a lower store built with stone and upper levels made with brick. The central higher block is adorned with a christogram, the Medici coats of arms (added when Siena fell under Florentine control, more on that later), the city’s coat of arms, and a lion. The latter is a reference to the legend which traced Siena’s origins to Senius and Aschius, the sons of Romulus. At the top, the building displays a crenellation in the distinctive Guelf style.
In the 13th and 14th centuries, the opposition between Guelf (from Welf, the Bavarian dynasty of dukes competing for the imperial throne), sympathetic toward the papacy, and the Ghibelline (from Waiblingen, the name of the Hohenstaufen castle), supporters of the emperor, caused division within the northern Italian city. Siena was initially a prominent Ghibelline city in Tuscany, famously defeating Florence (a Guelf city) at the Battle of Montaperti in 1260. Following a series of defeats of the Ghibelline, however, Siena slowly shifted toward the papal faction. In 1287, when the Council of the Nine was established, the Tuscan city was already Guelf.
Today, the town hall houses the Sienese administration (in the right wing) and the Civic Museum. Among the frescoes adorning the town hall’s interiors, visitors can admire Simone Martini’s Maestà and Ambrogio Lorenzetti’s The Allegory of Good and Bad Government.
In the second half of the 14th century, the Torre del Mangia was erected on the left of the Palazzo Pubblico. At the time one of the tallest bell towers in Italy, the Torre del Mangia was named after its first bell ringer, Giovanni di Duccio “Mangiaguadagni” (profit eater). A crack at the bottom of the 1666 bell, known as Campanone (The Big Bell) for its size, gives it a distinctive sound. Visitors who climb the 400 steps to the top of the tower are treated to a breathtaking view of Siena’s city center.
3. Cathedral
The Sienese Duomo (Cathedral), also known as Saint Mary of the Assumption, is one of the major landmarks of the city, visible from almost every angle thanks to its high bell tower.
According to unconfirmed rumors, the cathedral, featuring a unique mix of Romanesque and Gothic elements, was built on the site of an ancient Roman temple of Minerva to replace an earlier church dating back to the 9th century. There is also no recorded evidence to prove that the cathedral was inaugurated in 1179 with a ceremony attended by the Siense Pope Alexander III after reaching a peace treaty with Emperor Federick Barbarossa.
Construction of the cathedral likely began in the 12th century. In the second half of the following century, Nicola Pisano and his son Giovanni oversaw the realization of the lower layer of the imposing facade, built in a Romanesque style. Later works added Gothic elements to the existing structure. The alternating white and greenish-black marble stripes in the lateral walls and the interior are a reference to Siena’s coat of arms, a black and white shield.
In 1339, the municipality planned to extend the cathedral by adding a nave and two aisles. The outbreak of the Black Death, however, halted construction. The 14th-century plague ravaged Tuscany, causing death and damaging the economy of the hardest-hit cities. The project was permanently abandoned after the end of the pandemic, as structural failures were detected.
Over the centuries, most of the most prominent Italian artists worked for the cathedral. Nicola Pisano sculpted the pulpit between 1265 and 1268. A bronze statue of St. John the Baptist by Donatello adorns the eponymous chapel, while Michelangelo created the St. Peter, St. Paul, St. Pius and St. Augustine statues for the Piccolomini altar. Duccio di Buoninsegna worked on the designs for the stained glass window above the apse, and Gian Lorenzo Bernini created the lantern visible atop the dome.
One of the most impressive features of the cathedral is undoubtedly its marble floor, described by Art historian Giorgio Vasari as the “most beautiful…, largest and most magnificent floor ever made.” The result of a project spanning from the 14th to the 19th century, the floor showcases a mixture of graffiti and mosaic marble inlays. It depicts scenes from the Old Testament, sybils, allegories, and mythological figures.
Of interest is also the Piccolomini Library, which visitors can access near the Piccolomini Altar. Commissioned in 1492 by Francesco Todeschini Piccolomini, the archbishop of Siena and future Pope Pius III, the library displays the illuminated manuscript codices collected by his uncle, Pope Pius II (Enea Silvio Piccolomini) in Rome. The room is adorned by a series of frescoes by Pinturicchio and his school celebrating Pius II’s life and painted between 1503 and 1508.
4. Battistero
Located alongside the steep marble staircase leading to Piazza Jacopo della Quercia (where visitors can see the remains of the unfinished “New Cathedral”), the Battistero (Baptistry) showcases artworks from the early Sienese Renaissance period.
In the fully decorated interior, visitors can admire the fresco cycle made by Lorenzo di Pietro “Vecchietta” between 1447 and 1450. In the vaults, the artist painted a cycle explaining the Twelve Articles of the Christian Faith while he adorned the apse with frescoes depicting the Assumption of the Virgin in Glory with Angels, the Annunciation, and scenes from the Passion of Christ.
In front of the apse is the Baptismal Font, a hexagonal marble basin adorned with bronze reliefs and statues. The most notable panel was added by Donatello in 1427 and depicts the Feast of Herod. His first relief sculpture, the panel highlights the artist’s exemplary use of perspective, a technique introduced a few years earlier by Brunelleschi.
5. Saint Dominic Basilica
The Basilica of Saint Dominic is located on the hill of Camporeggio, offering visitors a scenic view of the city center below. Construction began in 1226 after the Dominicans were given the land atop the hill from the Malavotti family.
The Basilica, built in the Gothic Cistercian style and made of brick, was later enlarged in the 14th century, and its interior follows an Egyptian cross plan. Over the centuries, several calamities damaged the building, such as a series of fires in 1443, 1456, and 1531 that destroyed much of the 14th-century Gothic features. In 1798, an earthquake almost demolished the entire Basilica and toppled the bell tower.
During the following restoration works, the Basilica underwent considerable changes that altered much of its former appearance. Today, the religious building is mainly known for its connection with Saint Catherine of Siena (link to article 3901), born in a house near the Basilica, and attracts pilgrims and believers all over the world. In 1363, at 16 years old, Catherine of Siena joined the Dominican order as a tertiary (a lay member who chose not to live in a convent or monastery) and became a frequent visitor of the Basilica. For this reason, the church is commonly referred to as Basilica Cateriniana.
In 1383, Saint Catherine’s biographer and confessor, Raymond of Capua, brought the mummified head of the saint to Siena. The relic is now displayed in a Baroque-style chapel in the interior of the Basilica.
6. Saint Catherine of Siena Shrine
Located in the Fortebranda district, just below the Camporeggio hill, the Sanctuary (or Shrine) of Saint Catherine is located in the three-stories house where the saint’s family lived. Jacopo di Benincasa rented the building in the 14th century, turning it into a workshop for his dyeing business and a home for his large family—Jacopo and his wife Lapa had 25 children, though most of them did not survive to adulthood.
In 1466, after Catherine from Siena was canonized by the Catholic Church, the Sienese comune (Italian for “municipality”) agreed to buy the building following a petition by the neighborhood’s residents. Over the centuries, the house became a shrine to Saint Catherine. In 1941, every Italian comune covered the symbolic cost of a brick to build the portico dei comuni (portico of the municipalities) that runs along the ground floor of the building.
In the Church of the Crucifix is perhaps the most prized possession of the sanctuary: the wooden crucifix from which Saint Catherine of Siena is said to have received the stigmata. In the Catholic faith, the stigmata is a series of marks similar to those inflicted on Jesus’ body during the crucifixion, in 1375. Previously located in Pisa, the Tuscan city where the miracle took place, the 13th-century wooden crucifix was brought to Siena in 1565.
In the shire, visitors can also enter the Oratory of the Bedroom, the room where a young Catherine spent her younger years fasting, praying, and meditating.
7. Palazzo Salimbeni
Located in the homonymous square, Palazzo Salimbeni is the headquarters of the oldest surviving bank in the world: Monte dei Paschi di Siena. The origins of this credit institute date to 1472, when the Republic of Siena established a Monte Pio (pawn agency) as a means to curb the spread of unchecked usura, the practice of usury.
In 1866, five years after the unification of Italy, the Monte Pio merged with the bank, and Palazzo Salimbeni, named after the Salimbeni family who used to own it, became the institute’s official headquarters. In 1624, Ferdinand II Medici, the Grand Duke of Tuscany, offered depositors of the Sienese credit institute to guarantee their funds with the value of the paschi, the state-owned pasture lands in the Tuscan Maremma, thus giving the bank its present-day name: Monte dei Paschi.
In 1877, the palazzo’s facade underwent a series of changes through the restoration efforts led by Giuseppe Partini, who added neo-Gothic elements to the building. In the 19th century, a statue of Sienese archdeacon and economist Sallustio Bandini, carved by Tito Sarrocchi, was added at the center of the square.
Today, Palazzo Salimbeni houses not only the Monte dei Paschi’s headquarters but also a remarkable collection of Sienese art and the bank’s historical archives. The collection opens to the public only twice a year when Siena hosts the famous Palio.
8. Medicean Fortress
In 1554, Duke Cosimo I de’ Medici launched an attack against Siena to punish the city for its pro-French policy and for giving refuge to exiles from Florence. At the time, Cosimo I, elected as head of the Republic of Florence in 1537, was pursuing a policy of territorial expansion in Tuscany with the backing of Holy Roman Emperor Charles V.
Siena put up a courageous defense but finally capitulated in 1555 after a long siege. The following year, Philip II of Spain officially granted Cosimo I lordship of the rival republic. In 1559, after the Peace of Cateau-Cambrésis, the treaty marking the end of a long struggle between France and Spain for the control of the Italian peninsula, Siena found itself isolated and was forced to surrender to Florentine rule. In the following years, Cosimo I conquered much of Tuscany, becoming the first grand duke of the region in 1569.
After defeating Siena, Cosimo I sought to reinforce his control of the rebellious city to prevent the Sienese government from regaining its independence. As part of this policy, in 1561, the Medicean duke ordered the construction of a fortress on the site where once stood the Cittadella, a fort built on the orders of Charles V in 1548 after invading the town. The citizens of Siena destroyed the Cittadella a few years later when they rebelled against Spanish rule.
Today, the Medicean Fortress, located just outside the city center, is a public park and the location of outdoor festivals. It also houses the Siena Jazz Foundation and the Enoteca Italiana di Siena, a wine-promoting organization. Built in a quadrangular shape, its four pentagonal bastions offer visitors a scenic view of the city center.
9. Santa Maria della Scala
Santa Maria della Scala (St. Mary of the Stairs) houses a museum, various service areas, and exhibition rooms. A former hospital, the massive building facing the Cathedral is the result of several architectural stratifications.
The first levels, a network of tunnels excavated in sandstone and brick rooms, are now used for the Archaeological Museum. The fourth level opens to Piazza Duomo and once housed the male pilgrims’ ward, the largest healthcare space of the building. A series of frescoes painted between 1441 and 1444 shows visitors the story of the hospital and depicts its main functions.
The women’s ward, located on the levels above Piazza Duomo, is now used for temporary exhibitions and houses the Piccolomini-Spannocchi collection.
10. National Picture Gallery
The National Picture Gallery is a must-see for art lovers. Also located in Piazza Duomo, the museum houses an impressive collection of paintings from the Sienese school, displaying artworks from a wide array of periods, from the Renaissance to the 17th century.
Opened in 1932, thanks to art historian Cesare Brandi, the National Picture Gallery displays masterpieces by the most influential Sienese artists, such as Giovanni di Paolo, Pinturicchio, and Francesco di Giorgio Martini.
