I'm a bird watcher. I go birding every week. I built many sub-hobbies around it: photography, birdsong recording, blogging, cross stitching, and more. I find that when I'm out in nature, I can truly disconnect from my regular life stress and just be present in the moment.
I took this further by training and becoming a Master Naturalist though my local region's chapter. This opened the door to a great community, learning, and volunteer work.