In my case, it was at the public library. The lone internet computer was constantly booked. But by watching over a library clerk's shoulder, I was able to see the password needed to unlock the text-based library catalog terminals (which terminals were plentiful and always available). (My parents worked at the library, or else I never could have pulled that off.) Once unlocked, I was able to use Lynx to telnet into my favorite MUD game. Unfortunately it didn't last long until a librarian caught me, which I think resulted in me being grounded from the library for a month or something like that.
