The building was built by Cass Gilbert, the architect of the U.S Supreme Court and the Woolworth building.
It was originally made for children with tuberculosis, and opened in the 1930's, but then in 1958 it was changed to a elderly home for a few years. The Seaside has had a few names, like Seaside Sanatorium, Seaside Geriatric Hospital and Seaside Regional Center for The Mentally Disabled. Then it was used for people with developmental disabilities. In the 1970's, it was uncovered that some patients were being violently abused by staff and in the 1990's more patients were passing away then usual. Seaside was then closed in 1996 and the government made the land into a state park. The building has been vacant for two decades.
Access: It's inside a park now with lots of people and security guards. Their are fences and some buildings are boarded up, but I think if you wanted and went on the right day when no one was there, there are holes in the fences and some windows and doors are broken that you could access.