I love these free University classes online. Places like Coursera, EdX, even LinkedIn Learning offer great courses you can take on nearly anything you find interesting -- both professional and personal. Of course they offer a paid version where you can get a Certificate at the completion of the class for $149, but if you're just interested in the information you can "audit" the class for free.

The one that jumped out at me from these Harvard University offerings was "Women Making History: Ten Objects, Many Stories". I have two daughters so I'm always interested in learning things that I can pass along to them that might inspire them some day. 

It'll have to wait in line though until I've completed my "Music of the Beatles" course on Coursera.  :-)