New York City's only landmarked ruin: the Renwick Smallpox Hospital

The Smallpox Hospital, also known as the Renwick Smallpox Hospital, was a hospital located on Roosevelt Island in Manhattan. Originally designed by architect James Renwick Jr, the 100-bed hospital opened in 1856 when the area was known as Blackwell's Island. It was situated on the isolated southern tip of the island in an attempt to quarantine patients. It contained a large charity ward in addition to private rooms on the upper floors.

In 1875, the hospital closed and became a training center for nurses attached to City Hospital, later renamed Charity Hospital. Two wings with the same architectural theme were added to the school between 1903 and 1905 to accommodate a growing student base. The buildings eventually fell into disrepair as they became obsolete, with both Charity Hospital and the nurses school closing in the 1950s. In 1972, the hospital was added to the National Register of Historic Places, making it New York City's only landmarked ruin.

The building is a three-story, nine-bay U-shaped structure faced in granite veneer. While designed in the Gothic Revival style, all of the windows on the third floor have pointed arches rather than curves, which is unusual for that architectural style. After a $4.5 million stabilization project, the ruins will be open to the public as part of the Franklin D. Roosevelt Four Freedoms Park.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons