This has to be seen to be believed: Adventure Generator!
It uses geomorphs based on those by Dyson Logos, encounters from your choice of Moldvay Basic or Moldvay/Cook/Marsh B/X, and dressing from AD&D’s DMG.
Now, I’ll admit that I’m not sure how much I’ll actually use this. The repetitive nature of large geomorph-based dungeons is off-putting (at least to me). But the scale of the thing and fun of scrolling through quick random megadungeons is mind-boggling.
I dare you to not try whipping up a couple just for fun.