If you have some green areas near you try climbing trees. It's a pretty weird hobby and you can start with what feels like humiliating small steps (climbing a hip-height branch). But it's a great way for getting a different and closer appreciation for nature and also of exercising balance and body control rather than just the muscle growth you'd get at the gym.

I also second martial arts, specially more cultural ones like Capoeira, Kung Fu or Karate rather than competition-focused ones like Boxing.