6th Ave. There's one called "The Green Room"

After you try that, head up to Edgewood via Maridian, and you'll see this little tiny convenience store accross from a gas station and beside a bar. It'll be on your left. Go in there, and if there's a lady working there, ask to see the pipes. She'll gladly help you.

Have fun!

:P And hi, Tessa. imp: