Belatedly, World-Building Month

Some of my friends did a world-building month in February and I wanted to join in, but I just couldn't. I didn't have enough spoons--or perhaps pencils would be a better metaphor, in this case. I wasn't quite tired enough to evade feeling envious, though.

So I've decided I'm going to do a world-building month in April instead, and am combining it with the April A-Z challenge. Now all I need is topics for every letter of the alphabet!

If I have to, I suppose I can make up topics myself, but it's more fun if friends challenge and inspire me. I'm collecting prompts over here.  Or you can leave questions or other prompts here.

It's good to see you all!