Manhattan Waterfront Greenway or what I call their bike path. We only walked about 5+ miles (about 11,500 steps according to my Fitbit pedometer) of the 32 mile course. But it was a lot of fun and we had beautiful weather - we forgot that it was already the second week of October. This course runs between the Hudson River and Riverside Drive and travels all the way down to the GW bridge and then around Manhattan I believe. People were out roller-blading, walking, jogging, biking, kayaking on the Hudson and even saw one older guy doing some cross-country dryland skiing - with poles and all. We saw a second older gentlemen doing some boxing by the rivers edge with make shift silver punching bags. I saw that same person about three miles down river walking up the stairs (48 steps to the top) and was actually carrying the punching bags that he was hitting down river. He had to be in his mid-60's and was in pretty good shape - even though he was pretty wiped doing the stair-workout which of course I had to try (without the punching bags though).