I'm familiar with Bitcointalk and Altcoinstalk, but recently I stumbled upon a site listing 17 other crypto forums.Here's the site,you can check out them for yourself- https://cryptolinks.com/cryptocurrency-forum. I'm not sure how active they are since I didn't sign up.Are you interested in exploring these forums or just learning about them? I'd advise caution,as some crypto forums can be fake or untrustworthy.I've actually discussed this topic on my local forum- https://bitcointalk.org/index.php?topic=5519822.msg64754862#msg64754862.