In the closing decades of the 19th century, New York underwent a profound physical and cultural transformation. Fueled by the wealth of the exploding financial and manufacturing sectors, the city rapidly evolved into a world-class metropolis. The bold ambitions of civic and business leaders, architects, and engineers of the era manifested in landmarks such as the vast Cathedral of St. John the Divine, the stately U.S. Custom House, the towering Municipal Building, and the original terminus of New York City’s first official subway line—the ornate City Hall stop. The sweeping interior spaces common to all of these structures, and hundreds of others, depended upon a venerable Mediterranean building technology adapted to contemporary American construction: arched tile ceilings—or vaults—that were not only self-supporting but could also bear the weight of floors or roofs above them. These vaults were designed and built by a single New York firm, founded by Spanish immigrant Rafael Guastavino (1842-1908) and later headed by his son Rafael Jr. (1872-1950). The Guastavinos’ patented system for building domes and vaults involved multiple layers of thin ceramic tiles bonded with quick-drying mortar. The resulting structures were not only exceptionally strong, but also lightweight, easy to build, and inherently beautiful, thanks to intricate patterns of exposed tile that formed finished, decorative surfaces. Guastavino vaults figured prominently in more than 1,000 projects across the nation, including 200 in Manhattan alone. During its 73-year history, the Guastavino Company helped build some of the most impressive interior spaces in America—veritable palaces for the people. This list based on MCNY's exhibition Palaces for the People, contains many of Guastavino's masterpieces in the five boroughs, both those that remain and those that have been lost to the wrecking ball.

Church of St. Teresa, November 23, 1932. St. Teresa Catholic Church has occupied this Gothic Revival building since 1863 , but the edifice was not built for them. Completed 21 years earlier, the stone building was constructed as the Rutgers Presbyterian Church. The name of the architect has been lost to time, but he was at the forefront of ecclesiastical architecture. Here he chose an emerging style for New York City religious structures. The four clocks on the bell tower are considered the oldest hand-wound public clocks in the city. During the 20th century the structural integrity of the building suffered with age, culminating in the 1995 collapse of the vaulted ceiling, which rained 60,000 pounds of plaster though the main floor and into the basement. Facing possible demolition, the parish sold their adjacent property and air rights to fund the repair work. Along with this roof and interior reconstruction came also some restoration efforts, including work on the church's timepieces. The four belfry clocks had stopped functioning or their winding had long been ignored. (Photographic evidence suggests that the Rutgers Street clock face read 10:15 from the 1930s through the 1970s.) Today the church's facade, at nearly two centuries old, looks incredibly similar to what it would have looked like when built in 1842.