13. Lenox Hill Armory, 7th Regiment
Year Built: 1877-1879
Where: 643 Park Ave.
The Seventh Regiment Armory located on Park Avenue was designed by Charles Clinton in the Gothic Revival style and is known for its wonderful woodwork, ornament, and stained glass. It is currently being used as an art space by nonprofit Park Avenue Armory and has been featured in scenes of Boardwalk Empire. See some photos inside the armory here.