Does anyone know what this nightmarish building on Roosevelt Island is? #NYC pic.twitter.com/idwJcGHqAk
Marshall Maher (@Marvelle) February 21, 2014
More on the Renwick Ruins Smallpox Hospital from the Roosevelt Island Historical Society

Image of Renwick Ruin Smallpox Hospital From Olya’s Urban Journal this previous post. and cool video of the Ruins mistaken for a Scottish Castle.
