Example Dungeon?

[Forte]

Just curious since I recently noticed that is wasn't in the 4ed rulebooks, is the example dungeon used throughout the 3ed/3.5 DMG from something specific or is it just an example dungeon? I recall that same dungeon being in the 1st edition AD&D DMG as well (I found it particularly funny to remember the part about the party's torch spoiling infravision and the newer version made a similar quip about not spoiling darkvision). I never really had the 2nd edition rulebooks, so I don't know if it was in there.

[jiriku]

I'm pretty sure it's just a sample, but it was nice to find that as an Easter egg for those of us who started with the 1st edition rulebooks.