Looking for some good music venues in Charleston

Hey all, looking for some good local music venues around here. Under 21 admission is a must. I want to get into the local metal/hard rock/punk/hardcore whatever scene, and I was wondering if you guys knew what spots might be good for that stuff specifically? Open mics are a plus too! Thank you guys so much, I tried looking myself and most of the ones I find seem to be 21+ only (being bars, I understand)