Have you ever noticed the vaulted tile ceilings of the Oyster Bar inside the Grand Central Terminal? Have you ever walked under the polychrome tile arches and vaults of the Elephant House of the Bronx Zoo? The Museum of the City of New York is revealing a secret kept for decades behind many iconic American public buildings. At least 200 of New York’s most prominent Beaux-Arts landmarks were built more than a century ago by a father-son team of masons from Spain. Not only did Rafael Guastavino Sr. and his son (also named Rafael) help build some of the nation’s most iconic structures between 1881 and 1962, they also revolutionized American architectural design and construction with their tile-vaulting system.

Guastavino tiles seen inside the Holy Trinity Roman Catholic Church on West 82nd Street in Manhattan. Michael Freeman

Rafael Guastavino Sr. WikiMedia Commons Once you identify some of their architectural chef-d’oeuvres, you’ll start seeing them all over. Their ceilings grace landmarks around the country from the Nebraska State Capitol to the dome of the Smithsonian’s Natural History Museum in Washington, D.C. They even ornament ordinary buildings. One of them is the Engine No. 3, a small brick firehouse built in 1916 not far from the U.S. Capitol. Although they helped build more than 1,000 buildings in 11 countries, the name Guastavino remained largely unknown. In an effort to shed light on the story of these avant-gardist architects, the Museum of the City of New York has just opened the exhibition “Palaces for the People: Guastavino and America’s Great Public Spaces,” running through Sept. 7. Originally curated by John Ochsendorf, a 2008 MacArthur Fellow and professor in architecture at MIT, the exhibition first opened in 2012 in Boston. It was the result of a seven-year cooperation between Ochsendorf’s team and the city’s public library. Last year, the exhibition moved to the National Building Museum in Washington. The latest exhibit is substantially expanded to highlight some 20 key Guastavino spaces in New York’s five boroughs.

The forgotten masons

The Guastavinos' polychrome tile arches and vaults adorn the Elephant House at the Bronx Zoo. Michael Freeman

In his 2010 book "Guastavino Vaulting," Ochsendorf tells the story of “the unnamed, talented, master craftsmen, who haven’t really been celebrated.” “It's almost as if they were dropped here from the 14th century into early 20th century U.S., building some of the greatest buildings our country has ever known,” he said. In 1881, the Guastavino family emigrated from Barcelona, bringing with them an Old World masonry technique that was embraced by some of the top architects, including Charles McKim, John Carrère and Thomas Hastings. They used thin ceramic tiles that they set in cement mortar and layered on top of each other. “The Guastavino construction method was absolutely revolutionary in its day for three big reasons,” Ochsendorf said. “It was fireproof; it was incredibly strong; and it could be built with no support from below during construction, almost like magic.”

At the time, there was a building boom in America, and massive fires – like 1871’s Great Fire of Chicago that destroyed 19,000 buildings – were gutting cities made of wood. “So you could imagine that if your city could go up with a match, there was a lot of interest in how can we find a way to make buildings that won't burn down?” Ochsendorf said. As the Guastavino Fireproof Construction Company established its name in the industry, demand for the family’s work soared. “The key is getting the geometry right. And they were masters at getting geometries that were very strong,” Ochsendorf said. To reveal the precision and craftsmanship of the Guastavino work, masons from the International Masonry Institute and students from MIT created a half-scale replica of the fireproof vaulted ceiling the Guastavinos did in 1889 at the Boston Public Library.

Their designs weren't just strong; they were also beautiful. One classic example is the Guastavino's City Hall subway station hidden in downtown Manhattan, often referred to as the Mona Lisa of subway terminals. “When it was first opened, it was called an underground cathedral,” Ochsendorf says. “The subway had skylights, chandeliers, beautiful color tile, and sadly it's been closed to the public for about 60 years.” The station closed because it couldn’t accommodate newer, longer trains. “It's a kind of mystery space under the streets of New York today, but it's really one of their masterpieces,” according to Ochsendorf.

Architectural heritage

On the lower level of Grand Central Terminal, Guastavino arches soar above diners' heads inside The Oyster Bar. Michael Freeman

Creating grand buildings became fashionable, but with the tile process being labor-intensive and pricey, the Guastavino Company experienced a gradual decline as the Great Depression began. The architectural styles also slowly changed: the use of reinforced concrete grew along with the rise of the angular International Style of architecture. “When that movement died out and the sleek, straight lines of modernism became to rise in the ‘30s and ‘40s, that really kind of helped to phase out Guastavino,” Ochsendorf said. While at least 650 of their buildings still stand in about 40 states and several countries, the Guastavino name is still largely unknown.

Click to view an interactive map of Guastavino projects across the U.S. from palacesforthepeople.com palacesforthepeople.com Ochsendorf first learned about Guastavino in 2000 as a Fulbright scholar in Madrid. He was working in an architectural office where staffers were assembling an exhibit on Guastavino. Today, he and his students at MIT are hoping the Guastavinos can get their moment in the spotlight . “We are trying to document their works, to raise awareness about them and to try to help prevent them from being damaged or torn down,” Ochsendorf said. “I realized their buildings were all around me. “My passion for the subject just grew over time, and it's kind of an infectious disease,” Ochsendorf said. “I call it Guastavino-itis.” Ochsendorf says that more and more people are on the hunt for Guastavino sites, which are hidden in every nook and cranny of the country. He also created an interactive map to keep track of the latest discoveries.