Forum 7
Forum 7 was - on the old NationStates forums before the switch to Jolt - skipped in the forum numbers. There was a forum 6 and 8, but not a 7. It was figured out that it was a forum that only moderators could see, but that didn't stop a conspiracy from developing. Many conspiracy theories were formed around this mysterious "Forum 7."
On April 1st of 2004, Max (among other April Fool's jokes) created a forum entitled "Forum 7" which remained until the switch to Jolt. There, many conspiracies were made and quote temples (quote pyramids - made out of many blank quote messages) were put there, too. Another, deeper, conspiracy developed as it was found that "Forum 7" was really numbered 13. It was quite entertaining.