There are people in their 50's who act elderly, and there are people in their 80's who don't, it's more than just carrying an AARP card.

Circle line can be good (take the half trip, the entire city trip can get boring), If they are baseball fans the Yankees are at home that weekend playing the Mariners, tickets are available, neither requires much walking once you get there.

You will certainly walk more in Woodbury than in the city, it's very sparead out.