Mine is mapping. I am a big OpenStreetMap contributor and I have mapped many towns near me that were previously completely unmapped.
I just think all of the minerals and gems look so cool.
That’s where I’m at too. I said mineralogy, but really just because I didn’t know a concise way of putting “I just like how minerals look” in terms of an interest. Lol
Definitely agree on the Smithsonian, such a cool section!