New York City Lunatic Asylum
- 1841 - The Octagon, built in 1834 on Roosevelt Island, was designed by Alexander Jackson Davis as the entrance to the New York City Lunatic Asylum, which opened in 1841. Constructed from island-quarried stone, it is the last surviving remnant of the hospital. The asylum later became infamous through Nellie Bly’s 1887 exposé Ten Days in a Mad-House.