Randalls Island is the home to Icahn Stadium, golf and tennis centers and soccer, softball and baseball fields, however most of the island is parkland so you can bike around the island. There’s a waterfront path system and the best way to take it in all the nature and quiet pleasure is by bike. There are a lot of attractive areas in the island that you can visit.
Source: http://www.nytimes.com/2012/10/12/nyregion/randalls-island-paths-for-urban-biking.html
Pic Source: http://www.nationalparks.gov.uk/__data/assets/image/0008/351845/nf_woodlandcycling_ph.jpg