Bike Tour when in Lima, highly recommend.
DH and I spent 2.5 days in Lima. One of the best things we did was a bike tour with gogobiking.pe . We did the 3 hour Baranco tour. The guide was great, bikes were excellent and the riding not difficult. I'm 57 and in fairly good shape. Walk daily, golf, do some yoga. It wasn't hard and we thoroughly enjoyed it. I would highly suggest it ( and gogobiking specifically) if your are looking for something to do. Even after the ride, we walked 6 miles that day, so it wasn't too tiring!
We also did a bike tour in Santiago, 16km, and THAT nearly killed me!! That was a whole different experience.