The first church in the world built on a concealed steel skeleton

Located at 133–145 West 46th Street in Midtown Manhattan, the Church of Saint Mary the Virgin is colloquially known as "Smoky Mary's" because of the high amount of incense used in services. It is an Episcopal church of the Anglo-Catholic tradition, built for those who wanted to express Catholic thought in ritual and teaching within the Episcopal Church.

The current building was completed in 1895 because the congregation outgrew its first home. John Jacob Astor donated the land, stipulating that the church should be "free, and positively orthodox in management and working." The architecture is designed in the style of 13th and 14th-century French Gothic, featuring a limestone facade and a nave that reaches 80 feet from floor to ceiling.

The building is a technical feat: it was the first church in the world built on a concealed steel skeleton. The steel framing of the church is buried within the walls. To ensure continuity, the marble high altar was moved from the former church to the new chancel.

Today, it remains a New York City landmark and is listed on the National Register of Historic Places. It still serves a congregation that maintains the traditions of the Anglo-Catholic tradition, keeping the church's unique structural history preserved within its masonry.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons