St. Mary of the Angels Catholic Church in Chicago is an example of the Polish Cathedral style of churches. It has been acclaimed as one of the finest specimens of Roman Renaissance architecture in the United States.
Notre-Dame Basilica - Basilique Notre-Dame: The oldest catholic church in North America built in 1656. A magnificent cathedral with an intricately designed interior including stained glass chronicling the history of the City.
Loretto Chapel - Sante Fe, New Mexico! One of my fave cities! Love the history of the city and this beautiful chapel! Be sure and check out the story of the "miracle staircase": http://www.lorettochapel.com/staircase.html