Guarino Guarini’s Astonishing Baroque Architecture in Turin

What does a tunnel to heaven look like? The answer floats – against all laws of physics – within a chapel which should be too small to contain it. Turin’s architectural miracle combines advanced mathematics with lessons in perception from ancient Greeks and avant-garde Baroque masters. The city’s buildings have been quietly bowling people over for centuries, none more than those of Guarino Guarini. With just a handful of structures, Guarini introduced architecture to a profoundly different type of geometry – and reinvented the dome in the process. 

With a flair for the dramatic to rival Bernini and a command of form beyond even Borromini, Guarini explored ways to visualize the infinite. His three most important surviving works all lie within a few blocks of one another in central Turin. Architecture fans can find plenty to see in the city, but these buildings alone merit a trip.

Guarino Guarini

Born in 1624, Guarini left his hometown of Modena to study theology, philosophy, and mathematics in Rome. Eight years later, he was ordained as a Theatine, one of the orders created during the Counter-Reformation to rehabilitate the church from within. Guarini began designing buildings while rising through the clerical ranks. He also lectured and wrote extensively on mathematics and physics while keeping up with the latest developments in optics and astronomy. His religious beliefs complemented most of the humanist theories of the period, particularly efforts to understand and define infinity. 

In Rome Guarini discovered Bernini and Borromini, whose work would influence him profoundly. But unlike most Italians in the 17th century, he also learned from other architectural traditions. Various postings within his Order exposed him to a wide range of styles and techniques, from Greek and Arab-Norman buildings in Sicily to the Islamic legacy of Iberia. Sadly, only drawings remain of Guarini’s architectural work from his middle years: earthquakes destroyed his churches in Messina and Lisbon, while his church in Paris was later torn down.

What distinguishes Guarini’s architecture above all is his command of advanced mathematics. After encountering the new field of projective geometry in Paris, he devoted much of his career to developing it. His fluency of form allowed him to create buildings with one seemingly impossible transition after the next. 

Chapel of the Holy Shroud (Capella della S.S. Sindone)

Guarini arrived in Turin in 1666, about nine years into construction of a chapel to house the Holy Shroud. Wedged into a space between the cathedral and the Royal Palace, the Sindone chapel wasn’t quite an independent building, but it needed a distinctive space for the sacred relic. The previous architect, Amedeo di Castellamonte, handled this delicate situation by separating the chapel from the cathedral with a dramatic glass wall. Guarini inherited a construction site full of black marble, with the lower third of the structure completed.

Inky light in the stairs contrasts with bright illumination in the central space.

The chapel’s main entry-points take the Baroque passion for dramatic lighting to a whole new level. Guarini shifted the original floor plan to squeeze three circular vestibules around the outside. While one leads to the ducal palace, the others connect to the cathedral via stairways. By shrouding the stairs in darkness, Guarini forced pilgrims to act out their faith by ascending almost blindly. Emerging from the blackness, they would finally step amongst the golden stars circling the Shroud. (Note that modern visitors enter the chapel via the Palazzo Reale.)

Stark black-and-white marble echoes the theme of light and dark, designed to evoke the suffering represented by the shroud. Instead of a hemisphere,Guarini presents a whole series of shapes piled on top of each other, culminating in what might be the world’s strangest dome. Amongst the many oddities of the chapel’s middle zone, Guarini created two kinds of surfaces: one with a complex network of stars and hexagons, and the other with crosses distorted to look like they are being stretched into a curve. The latter configuration was only possible with Guarini’s work in advanced geometry.

The “dome” is unlike any other structure in the world: six levels of hexagons, each composed of six arches, are stacked at alternating angles. By manipulating the proportions of each layer, Guarini created the illusion of a tunnel extending far beyond the building’s size. He enhanced the effect by using soft greys which mimic colors blurring in the distance, a trick he likely picked up from ancient Greek theories about perception.

The Chapel of the Holy Shroud comes at the end of a visit to the Palazzo Reale complex. See the website for more information.

San Lorenzo

The Royal Church of Saint Lawrence, or Real Chiesa di San Lorenzo, began with the renovation of an existing ducal chapel in 1562. Just over a century later, the reigning Duke of Savoy called Guarini to Turin to rebuild the church. Like the Chapel of the Holy Shroud, Guarini designed a centrally-organized space topped by a towering sequence of shifting shapes – and yet San Lorenzo is a strikingly different building.

A compressed hallway funnels into San Lorenzo’s main space. Here the very walls pulse inward, propelling visitors into the center. This is a contrast to the Sindone chapel, where everything radiates out from the sacred shroud. And unlike the other structure’s strict monochrome palette, San Lorenzo uses the full Baroque panoply of colors and decorations. Combined with the strange angles created by the curves, the effect is dizzying. 

Compared with the perimeter’s frippery, the middle of the church is remarkably open, and the eye inevitably rises up to encounter the building’s main focus. Like the Chapel of the Shroud, San Lorenzo features domes within domes, lit from windows on the bottom and (divinely) mysterious sources on top. But where the chapel’s primary dome has arches rotating about the center, this one has ribs criss-crossing the middle. One scholar calls the structure a “cat’s cradle of hyperbolic arches.” 

The design was a major departure from Western engineering. Instead of using the model pioneered by Brunelleschi in Florence, with supports radiating out from the center, San Lorenzo’s dome followed an Islamic design of interlacing arches. Presumably Guarini encountered buildings such as the Great Mosque of Córdoba with its 10th-century dome and appreciated its structural efficiency, since connecting arches eliminates the danger of buckling. He might have also been intrigued by Islamic architecture’s use of mathematics to evoke the divine through seemingly infinite patterns. 

Guarini put so many openings in his domes, historians refer to them as “diaphanous”. Like most Baroque architects, he viewed light as a symbol of holiness. Ironically, local audiences found something different: they discerned a “face of the devil” (faccia del diavolo) in the lower dome. Each of the round windows makes a mouth, topped by a pentagonal nose, followed by smaller ‘eyes’ above.

San Lorenzo is open Monday-Saturday 9-12 & 3:30-6, Sunday 3:30-6.

Palazzo Carignano

In 1679, as work continued on Guarini’s churches, a member of the Savoy dynasty commissioned him to design a palace. The Prince of Carignano desired a massive structure which could incorporate a residence with administrative and cultural functions. The complex became Guarini’s primary work of secular architecture.

In the Palazzo Carignano, Guarini adapted the Roman Baroque to a secular building in Northern Italy. Most notably, the undulating façade borrows from Borromini’s San Carlo allo Quattro Fontane. Other similarities include the giant order of pilasters (embedded columns) spanning the upper levels and the way the central section seems to punch through the rest of the facade. (The giant pediment and bronze inscription on top were added later.)

Guarini’s biggest departure from the Bernini and Borromini is the use of brick on the exterior. This could be a nod to medieval architectural traditions in Northern Italy, which didn’t sheathe brick structures with marble.

As the Savoys increased their political power and territories across Europe, they added on to the Palazzo Carignano and finally moved to the even-larger Palazzo Reale. Guarini’s building continued to serve the government, particularly when the Carignano-Savoys spearheaded Italy’s unification movement in the mid-19th century. Thanks to their role in the Risorgimento, the dynasty served as the country’s monarchs until 1946.

The Palazzo Carignano was chosen to house the national Museo di Risorgimento, which offers access to ornate apartments and rotating historical exhibitions. However, many of the building’s grander spaces (including those pictured here) don’t require a ticket to visit.

Other Guarini Works in Turin

In the Santuario della Consolata, Guarini’s oval entrance hall and hexagonal chapel are all but overwhelmed by other renovations and additions.

The Collegio dei Nobili, which now houses the Egyptian Museum and Academy of Sciences, was once attributed to Guarini. Although it picks up on many of his motifs such as the lines of stars running up the exterior, it doesn’t display his structural dynamics.

Practicalities & Further Reading

Many of Turin’s historic sights cluster along the arcaded Via Roma, which terminates at the Porta Nuova train station. Frequent trains between Milan and Turin take as little as 45 minutes. It takes about 10 minutes to walk to Guarini’s buildings.

For more on Baroque architecture, see our post on Borromini’s work in Rome.