This month's museum pick...

The Trulli of Alberobello; A Living Architectural Museum

by Dea Adria Mallin

Apulia, or Puglia in Italian, is hot and dry in the summer months when the scirocco blows in steadily from Africa, as it has done from time immemorial.

At the start of the 21^st century, in the heat of an Italian summer, I boarded a throwback train in Venice that chugged and swayed and screeched its way down the Adriatic coast of Italy towards Puglia, as if the French TGV and the Japanese Shinkansen were mere futuristic glimmers. It was an all-night journey from Venice to the baroque city of Lecce, extending until noon the next day. There was no air-conditioning, but the windows opened so that you could hang over them and watch the landscape unfold as you ignored the sign that said, much as it had some thirty years ago, “Do not hang out the windows. E pericoloso!”   

So I hung dangerously over the windows and watched the strange landscape as we journeyed to this obscure region in the heel of the boot where nobody speaks English. Nothing monumental. Nothing even remotely connected to the Italy of a Baedecker Grand Tour, though the narrow peninsula divides the Adriatic from the beautiful Ionian Sea and the Gulf of Taranto. At 8 a.m. there was already a relentless sun bearing down on the flat fields where farmers were bending in half to pick summer’s bounty. My daughter had studied in the baroque city of Lecce in the region of Puglia the summer before, and we were returning for six weeks so that I could understand what she had fallen in love with.  

One of our excursion destinations from Lecce was Alberobello, a gently undulating, rocky landscape 1,378 feet above sea level. It is a tiny Pugliese town in the province of Bari, where lives unfold much as they did in medieval times. In his journeys, even Christ is reported to have stopped at Eboli, which is to say that he went no further south; Italy’s southern parts are mired in poverty and ancient ways, and Alberobello is further south than Eboli.

Almost 2,000 years after Christ, in 1996, Alberobello was added to UNESCO’s World Heritage List, and that has everything to do with the strange, absolutely unique, and utterly compelling trulli of Alberobello. There are the great Wonders of the World, and then there are the small wonders. The trulli are small wonders. Small architectural wonders.

Trulli. In the singular, trullo. These are the houses of Alberobello, a throwback to the prehistoric past. Here is a construction method for building shelter -- a primal need -- that functioned in prehistoric times and has survived intact to function in the contemporary world of the 21^st century.

In Alberobello, on thirty-seven acres, there are 1,400 trulli, grouped most densely along the Rione Monte and along Aia Piccola, designated as national monuments long before UNESCO noticed them. Seen from above or below, surrounded by vast fields of olive trees and vineyards, they form a kind of enchanted land.

The trulli are small, round, and domed. And they are organic, comforting, and pure. Contrast this with the current architectural idiom of angularity that rises terrifyingly into the air and threatens to topple, of rippling reflective surfaces that shift from moment to moment, of eruptions of hard-edged rhomboids and trapezoid projectiles like quartz crystals. The classic Greek ideals of harmony and balance have given way to technological feats in architecture that produce both unbounded energy and a profound, if unnameable, sense of malaise.  

Which may account for the busloads of tourists who, in the past few years, have come to seek what the trulli of Alberobello offer as antidote. In the terraced town, there are modest trulli (with birdcages hung in the doorways in the morning and strings of fava beans drying in entryways), and there are spectacular multiple trulli, some with a little summer kitchen trullo so that the heat of cooking never affects the interior of the main house.

Sometimes, there will be a lone trullo standing in a field, a single-domed structure designed to serve as shelter from the sun for animal herders and field workers. Sometimes, the trulli are used for hay storage, while simple, low trulli are used for raising chickens. Trulli are often seasonal houses, used during the olive and grape harvests, and later, to store and age the autumn wine.

The Construction of the Trulli

The exact origin of the trullo form of construction in Puglia is the subject of scholarly dispute. Similar shelter structures, using vaulting, have been found in Egypt, Mesopotamia, Greece, Dalmatia, Sicily, and Sardinia, but it is possible that the Pugliese technique was invented independently. A farmer clearing stones from his field to allow for cultivation would probably discover the technique on his own. But why not construction from wood? Early deforestation of suitable timber in the region led inhabitants first to the natural grottoes of cave dwellings and then to the trulli. The olive trees provided the wood for what furniture there was.

Basically, the trullo is a single-story dwelling, circular in shape, made of layers of dry, roughly worked limestone gathered from neighboring fields, with a cone-shaped roof built up of corbelled limestone slabs and crowned by what looks like a handsome chess piece.

Architecturally, trulli are remarkable examples of drywall (mortarless) construction. The oldest examples extant date from the 16^th century. Prior to that, a trullo was easier to tear down and rebuild than to repair. As the technique developed, the walls of the trullo became thinner and taller, and the more stable mortared construction was finally permitted after May 27, 1797 when Ferdinand IV, the Bourbon king of Naples, responded positively to the inhabitants’ pleas for freedom, so that the form at last achieved its maturity. Late innovations include smoke holes, chimneys, fireplaces, windows, and the joining together of two or more domed structures to form a larger and more complex set of interior spaces. And if the trulli of Alberobello look as if they are crowded against each other, in fact, many have generous walled gardens for apricot and peach trees and for beans, tomatoes, figs, and flowers. 

The backstory on the mortarless construction is purely political. The first count of Conversano was given lands and title in the Norman epoch, and through the years, more land, more noble titles, and more feudal rights accrued to his successors. By 1525, about forty farmers and their families had settled in the area that is today Alberobello, by 1616, there were two hundred inhabitants, and with inducements of long-term leases, extension of credit, and immunity for criminals, over 100 families by 1650.

Count Gian Girolamo II, an ambitious man who wanted to develop his holdings independently of Neapolitan and Spanish kings, circumvented the Spanish king’s edict requiring all new buildings to have his permission so that they could be taxed. The count, unwilling to share his revenue, required his subjects to build with stone, but without mortar, so that royal assessors making a surprise visit would see only the same number of trulli they had counted the year before. How so? Without mortar, all the new houses could be quickly dismantled and the stones scattered innocuously. When the assessors left, the houses could be reassembled.

By the end of the 18^th century, not only had the trullo construction been carefully refined, but the growing population of 3,500 was restless for freedom, and won it from feudal barons in 1797 -- after which mortar could finally be used!    

Lest the reader think that building a refined trullo was easy, here are a few words about construction from Edward Allen in his superb, out-of-print 1969 book, Stone Shelters: Trullo-building specialists, called trullisti, were highly skilled. Their stones were either loose and gathered in the fields or quarried by hand from limestone bedrock in the fields. Supplied with stone, the trullista began by scraping bare the bedrock which would become the house’s foundation. If a cistern had been dug, it was capped with a lime-mortared barrel vault which would become the support for the floor of the house. The rooms were then carefully laid out, and walls were built with an inner plumb face, an outer face of carefully squared unmortared masonry, and a core of tamped rock fragments and soil. Tiny window openings were spanned with a lintel stone, but a doorway required a carefully made true arch of dry stonework.  

Allen continues: For the construction of the vault, a pole was erected and plumbed in the exact center of the room. A knotted cord attached to the pole gave an accurate radius to guide the placement of each stone. The vault rose in horizontal rings, without formwork, each trimmed stone butted carefully against the stones on either side, projecting a predetermined amount over the ring of stones below. The tendency of the entire conical construction to collapse inward was resisted by the horizontal arch effect of each ring and by the horizontal friction forces between the rings. The pitch of the dome depended on the length of the stones used; longer stones produced a flatter pitch.

As the conical vault approached its apex, a large, heavy, flat stone was used to close and anchor the vault. Roofing made of flat stones called chianche and chiancarelle sloped and overlapped in order to shed water, and channels conducted rainwater from the roof down the walls and into a cistern where it could be retrieved with a bucket and rope.

The roofs of the trulli – whose limestone shingles weather to a dark grey but are sometimes whitewashed along with the sides -- absorb and re-radiate solar heat, and are universally used to dry the region’s abundant figs, fava beans, and tomatoes. To store the dried foodstuffs, the interior of the major dome in each house is fitted with a wooden tavolato – an attic platform reached by a wooden ladder.

To close the cone at its summit, each trullo used a decorative element, though not a heraldic one, called a pinnacolo, or pinnacle. Possibly inherited from pagan times as an appeal for divine protection, the pinnacolo takes such forms as the sphere, the cross, or the zodiac, but has no physical function and is chosen today for its aesthetic appeal.

I have seen commentary that calls the trulli "cool in summer and warm in winter," but in fact, they are cold in winter, when the thick walls and dome condense the moisture from cooking and even breathing. Italians are accepting of cold walls and simply wear layers of clothes against the chill.

Museo del Territorio

Il Museo del Territorio di Alberobello

Around the time that the town became a World Heritage Site, it got a museum. One source says that twenty-three trulli were joined together to form the large, contiguous interior spaces of the Casa Pezzolla, or Territory Museum, but the most reliable source says fifteen. The set of houses in the middle of the town was owned by Signore Pezzolla, and bought by the town council in 1986. By 1997, the complex was entirely restored. The regional history, tradition, and folklore are examined in the many large and small rooms. Two rooms are dedicated to “The Trullo Master’s Hands,” with extensive explanations of drywall construction and the tools used. Another room explains, insofar as they can be explained, the spires and symbology of the trulli’s rooftop closures.

I have spent time inside this spacious museum, and while the exhibition rooms are marvelously informative, at no point was I particularly aware that I was inside a complex of trulli. I have also been inside the smaller trulli which are private homes, and was at all times in awe of the functionality and livable qualities. 

Architectural musings

From an architectural standpoint, each form of building in Alberobello --  from tufo caves fifteen centuries before Christ, to centuries of drywall trulli, and recently to mortared stone vaulting in the trulli, and then in the post-WWII years of the 20th century to reinforced concrete -- represents the cheapest and most flexible form under a certain set of conditions. 

In the tufo caves, all construction related to the face of the cliff -- the only source of air and light. In the trulli, every space had to be roofed with a conical dome, and the stone structure could not be mortared so that at the approach of the tax collectors, every house built for an expanding population since the last tax collector’s visit had to be disassembled and made to look like the piles and outcroppings of limestone rubble. Once political independence from the king was won, mortared stone vaulting could be used, curved and buttressed to support the load. Both tufo and trulli construction had their architectural limitations. In trulli construction, for example, while efforts are made to square off the interiors and to build stone sleeping alcoves for children, decorating vaulted walls is not a simple matter, nor is blocking off space for bedroom privacy. Moreover, the trullo cannot be two-storied.

And reinforced concrete? As Americans know all too well, this is a technique that imposes no particular form, a technique that is without limitations. And yet, reinforced concrete will never produce an Alberobello, or the similar small Pugliese villages of Ostuni, Martina Franca, and Cisternino, where the circles of dry stones, the sunlit whitewash, the conical dome, and the pinnacle design against an eternally blue sky create a bemused joy. Concrete produces shopping malls, boxy towns, and tall boxed cities – all without limit – and, sadly, mostly without soul.

The 20^th century’s fascination with concrete and glass arrived very late in Puglia, and in small forgotten towns like Alberobello. By 1969, cognoscenti were mourning the approaching deaths of the last trullisti and lamenting that trullo-building was about to become a lost art. Curiously, it is the very backwardness of Puglia that saved the trulli, so that just as the world was tiring of modern architecture, and looking to the post-modernist for exhilaration and inspiration, they rediscovered the ancient trulli of Alberobello and took to them as if they were excitingly new.

For the architectural soul of Alberobello today, not only can you visit the trulli, but you can rent the trulli – or you can buy one. And, if it’s summertime in Alberobello, not only will you encounter the traditional festivals celebrating the olive and grape and the tomato and maybe the tarantella and pizzica dance forms, but you can go to a modern jazz festival too.