When you are next looking for an outing that is a little more Zen and a little less zoo, head to the peaceful, manicured Arnold Arboretum in Jamaica Plain. The grounds are open from sunrise to sunset every day; admission is free (although donations are welcome).
The Arboretum offers seasonal two-hour school programs for students in grades 3 to 6 that are designed to encourage the investigation of plant science. Classes are free for kids from Boston schools, $4 otherwise. One-day and multi-session horticulture, botany, and landscape-related courses are offered for adults of all levels.