Luke

This is a gem of an urban oasis. A short ferry ride from Manhattan or Brooklyn takes you to another world. One with only a few cars, lots of green space, biking opportunities, and amazing views. We went last summer before the first stage of renovations to the island were completed. We recently went back and were blown away by the improvements. Although all of the renovations aren't done yet, what has been done is magnificent. There are more places to bike and walk. There is a cool hammock grove with dozens of - you guessed it - hammocks. The island will be amazing once everything is done. I am not sure I will bring a bike next time, though. It is too congested with people and there aren't dedicated bike lanes so you never get to "full speed."
Check for events on the island. The first time we went happened to be the day of an old-time party with music and lots of flapper dresses. Arrive early enough to ensure a spot on your preferred ferry. The ferries are free first thing in the morning (from Brooklyn at least). The price the rest of the day is reasonable.