Unless you hack around it, the Forums are numbered by the vBulletin software in order of creation. So you can tell which ones were made first, and last.
Shortly after the glaciers receded, when Arnold von Winkelried was merely a member and Uncle Beer was still a nephew, the decision was made to create three archive forums as permitted by the old software then used to run the boards, and to store the best of the early threads therein.
These three fora did not survive the transition to vBB, and the lamentation of the TubaDiva was heard throughout the land.
The fora didn’t survive, but in vBulletin, they’re not really needed. And from what I understand, most of the threads in those fora were eventually recovered, and placed in their original locations. So no more lamentation on that count.
And a good thing, too… You really don’t want to hear a lamenting tubist ;).