I was a seasonal park ranger one summer during my undergrad years. I earnestly believe that was the most fulfilling work I have ever done, and will probably ever do.

My time was largely used to fix things around the park, perform landscaping, and working on new / existing trails. It was great to be outside, work with my hands, and being mentally engaged having to come up with solutions to problems with sometimes limited resources.

But the actual treat was seeing the work being enjoyed by visitors and knowing that for years to come untold amounts of people from all walks of life will be able to do the same.