4. Roosevelt Island’s abandoned Smallpox Hospital

Smallpox Castle on Roosevelt Island, viewed from the park

Built in 1856, Roosevelt Island’s abandoned Smallpox Hospital is the city’s only landmarked ruin. The Four Freedoms Park organization hopes to turn it into the park’s visitors center. We can expect to see a lot of development around the hospital and on Roosevelt Island in the years to come. Our guides explained that 12,000 people live on the two-mile long island, and transportation is key. Though there is little commercial development there, city planners hope that Roosevelt Island will be in the lead on new development, as businesses stake out territory in Brooklyn and Queens.