The largest Roman Catholic cathedral in the United States, St. Pat’s is also the seat of the Archdiocese of New York. Designed by James Renwick, begun in 1859, and consecrated in 1879, St. Patrick’s wasn’t completed until 1906. Strangely, Irish Catholics picked one of the city’s WASPiest neighborhoods for St. Patrick’s. The vast cathedral seats a congregation of 2,200; if you don’t want to come for Mass, you can pop in between services to get a look at the impressive interior. The St. Michael and St. Louis altar came from Tiffany & Co. (also located here on Fifth Ave.). A free app was created by the diocese recently, and provides an erudite tour of the premises. In the fall of 2015, Pope Francis presided over mass here.