@59034767 a lot of it resonated with me.

I've often thought about going on the obscure but interesting non-fiction book hunt, but have never committed.

I also recently discovered Ooh! Directory, so the other ones you mentioned got me more excited about going down those rabbit holes. And I have a just-for-fun site at https://coywolf.surf where I add all of the interesting places I find on the web and send people randomly to them, StumbleUpon style. So those will help grown that URL database 🙌