What is your favorite non-fiction topic to read about?

For me, it would be history (my major), languages, and art. The area of history doesn't matter. I'll read about medieval European, ancient Roman, 19th century American, Japanese...it's all good. Intellectual history is something I've been looking into more recently.

I'm not a STEM person, but those topics can be interesting too. There's no limit to my curiosity, even if I have a few areas of specialty.