OK I know I said not much Manhattan, but though this is *technically* in Manhattan, it's kind of off the beaten path. You can get there by subway (F Train) and there is a bridge, but it's from Queens to the island. There is also a tram, although it is closed for the summer as they are upgrading it.
It's a nice island to go over, walk around, maybe have lunch at the italian restaurant across from the Duane Reade, and check out the "haunted" Renwick Ruins. The Renwick Ruins are named after James Renwick, Jr. who designed the building, and went on to design, among others, St. Patrick's Cathedral. The building was a smallpox hospital. Unlike numerous other medical institutions built by the city on the island in the 19th century, the Smallpox Hospital was not planned exclusively for charity cases. Because of the seriousness and the contagious nature of the disease paying patients were also admitted. Although vaccination against smallpox was common medical practice by the mid-19th century, the disease continued to plague New York city. Smallpox often afflicted recently arrived immigrants, and therefore increasingly more stringent quarantine measures were instituted. As late as 1871 smallpox reached epidemic proportions in new York, while during the Civil War many soldiers as well as immigrants were stricken with the disease.
This is how it looked back in the day:
This is how it looks these days. At night, it is lit up by three spotlights, making it look a little eerie.
I'd say Roosevelt Island is a mini Manhattan. It had just under 10,000 residents back in 2000. It is between Manhattan to its west and Queens to its east. Running from Manhattan's East 46th to East 85th streets, it is about two miles long, with a maximum width of 800 feet, and a total area of 147 acres.There are apartment buildings, 2 schools, a few parks, some restaurants, a Duane Reade, even a Starbucks!! There is a grocery store and a hospital, so it's kind of like a small town, but happens to be part of Manhattan. The Ruins are between the South Point Park and the southern campus of the Coler-Goldwater Hospital. There is also a lighthouse on the northern tip of the island. The island is small enough that you can walk the whole thing, but there is a red bus that runs the length of the island if you need it. You can get some great pictures of the Manhattan and Queens skyline. A nice day trip if you get tired of the crowds in Times Square.