The New York Marble Cemetery is the oldest (dating 1831) and probably one of the hardest burial grounds to find in NYC.
Located in the East Village, and behind the Bowery Hotel, the cemetery gate - a beautiful gate by the way - is located at the end of a narrow alley leading from 2nd Avenue.
The cemetery is marked by plaques instead of tombstones and can be visited for only a few hours on the 4th Sunday of each month, from April through October.
Location: 41 1/2 2nd Avenue
Photo Credits: Courtesy of the New York Marble Cemetery, Beyondmyken