Baywatch on the Hudson (New Jersey)
Palisades State Park in Alpine. The trail is basically level. It just goes up gently, then is level for a while, and then goes down gently and continues right next to the Hudson. It did get rocky in some places so it wasn't smooth-sailing but I did manage a brisk 3.2 mph walk most of the way. Because of poor GPS reception, I took some readings out on the beach away from the cliff and trees but I think a simple radial search would have located the cache too as it wasn't hidden in a tricky manner.
Okay, well... I think that walk helped burn off the Quiznos Tuscan Chicken sandwich. But I had dinner after that and put the calories all back in. Heheh.