3. Sniffen Court, Murray Hill, Manhattan
Sniffen Court is located on 36th Street between 3rd Avenue and Lexington Avenue in Murray Hill. It may be the most “hidden” on our list because there’s an iron gate in front of the dead-end alley. Inside, there are 10 carriage houses, all built by John Sniffen between 1863 and 1864, later converted into apartments.