The Jerusalem Botanical gardens are a wonderful place for an outside walk. They often have educational programming and the plants are of interest, I'm sure, to botanists around the world. I always found it a pleasant place to spend an outdoor afternoon as well as to meet with friends at the Caffit Restaurant on the grounds. There are entry fees to the gardens, and it can get crowded when kids are off from school.
Yehuda Burla St 1, Jerusalem, Israel