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.

St. Jean Baptiste Church, 1913. The parish of St. Jean Baptiste dates to 1882 when it was founded to serve the long -established French Canadian immigrant population of the Yorkville section of the Upper East Side. The community first worshiped in the hall above a stable on East 77th Street, referred to as the “Crib of Bethlehem.” A purpose-built church was erected between 1883 and 1884 in a simple Gothic style. The church became both popular among the larger Catholic New York community and the home of eucharistic worship in the decades surrounding the turn of the century. The community recognized the need (and desire) for a larger and more "worthy" (in pomp and decoration) structure and their prayers were answered with the entrance of a benefactor in 1910. Financed by American tobacco, insurance and transportation tycoon, Thomas Fortune Ryan, the present church building was designed by Nicholas Serracino, an Italian architect, and completed in 1913. The domed church (one of only a few Catholic churches in the city that feature a dome) was rendered in a combination of Italian Renaissance Revival and Classical Revival architectural styles. The main dome reaches a height of 172 feet. The interior is richly decorated with stained glass windows brought in from the glass studios of Chartres, Frances.

A walk of the best tourist spots New York City's Upper East Side has to offer.

Saint Jean Baptiste Church ARCHITECT: Nicholas Siracino DATE: 1910-13 STYLE: Church The principal facade on Lexington Avenue is a masterpiece of lively symmetry with a tasteful and intelligent statement and restatement of architectural motifs. A temple-front portico screens the central door of the three that gives access to the Church. Four free-standing Corinthian columns, on a high plinth, support a full entablature and pediment.