Santa Fe is filled to the gills with old churches. The San Loretto Chapel is one of them. It was built in 1873 and patterned after the Sainte-Chappelle church in Paris.
San Loretto is famous for its circular staircase that apparently amazes architects and engineers alike. It makes two complete 360 degree turns with no central support or other visible support. There is a mystery surrounding the person who built this staircase and the lore says it was either Jesus or St. Joseph. Somewhere I read they finally determined it was a French master carpenter. Anyway, the chapel was beautiful and the staircase was cool. It was hard to get photos of it because it's closed off and you can't get too close to it.
The photo above is a photo of a photo showing the stair case before rails were added.