Yep! Three full adventures, 80 encounter areas, and a "Random Dungeon Generator" for when players go off-map.I'm sure i saw suggestions of an Undermountain set coming out next year.
Also in terms of "mega dungeon", there's Tomb of Horrors, which had 4 separate dungeons. Granted it spans the level spectrum, so it's not in one complex.
Although honestly I think it'd be fairly easy to create your own megadungeon by stapling a few adventures' dungeons together. For instance, I think Pyramid of Shadows is crap as an adventure, but tearing out some of its areas and attaching them to a pre-existing dungeon would work so well. Same with Thunderspire Labyrinth - the Well of Demons would make a great chamber in some adventure.
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