Great day hike, especially for easy access from NYC. You can take Metro North right to the "Breakneck Ridge" stop (there are, I believe, about two trains that stop there in the morning and two returning trains in the evening on the weekends). One trail head is just south of the train stop - though the train makes for a very crowded trail because everyone debarks the train at once. Also, be far warned that the trail involves scrambling up rocks - it is infamous for skinning people's knees. If you are uncomfortable with heights, don't bother with Breakneck. Other than being far too crowded, the trail offers sumptuous views of Storm King and the Hudson (including a mysterious decrepit castle on an island in the river). The hawks made a nice showing when I was there, riding rising thermals up and around the hills. If you scrambled up the white blazed trail south of the train stop, an easier red blazed trail will take you down to the bottom, instead of scrambling back down the boulders (the red trail can easily be found without map, just by continuing along the white blazed trail). Go there in peak fall foilage, fill your nalgene with wine, and find a ledge to chill out on.